[26]

(12

First for the non-nitrogenous fluids. As a preliminary trial I placed a drop of water on very many leaves & it produced no effect, as indeed might have been anticipated as otherwise every heavy shower of rain would cause the leaves to contract.
cont p. 13 [pencil insertions not transcribed]

(In Generally the drop placed on the leaves was nearly as possible of the same size but I occasionally placed larger & smaller drops.  & In the case of water & other thin fluids the drop was with some exactness half a measured minim. Only a single leaf was operated on on each plant; & the plant came from two districts; & the experiments were tried during August & September

Gum Arabic, of three strengths very thin, moderately thick & so thick as hardly only just to drop; tried on eleven leaves & left on them from 24 to 44 hours, in most of the cases from above 30 hours; produced no inflection.

Syrup of white sugar, of two strengths, tried on eight leaves & left on from 32 to 48 hours; no effect produced excepting that in one specimen two marginal hairs were inflected.

Starch, made about as thick as cream, tried on six leaves, left on for 30°: no effect produced.

Acetic Acid, two minims to one oz of distilled water; just perceptibly acidulous, tried on six leaves left on for 24° produced no effect.

[See Insectivorous plants, pp. 77-78.]

[27]

Wine, (sherry), tried on three leaves left on for 31° & 41° caused no inflection, but seemed to injure two of the leaves.

Olive Oil, tried on three leaves, left on for 30°, produced no effect.—

Hence Thus, excluding the leaves tried trials with plain pure water, 38 leaves were tried experimented on with the foregoing non-nitrogenous fluids fluids; & no effect was produced with the exception of two marginal hairs in a single case with syrup, due I cannot doubt to some accident, such as a fly having alighted on them & then escaped. (In making this statement I must remark on one cautious remark, that when any gland adhesive fluid is placed on an old or feeble leaf, of which the glands do not secrete copiously the fluid will gradually dry & necessarily draw together the any hair which it has touched: I have seen this occur with a drop of plain water, which had first been rendered viscid by the secretion. The only safe criterion & which alone I have trusted in all the following experiments, is the inflection of the marginal & extreme sub-marginal hairs [illeg] which have not been touched by the fluid or of which the extra base alone have been touched. The action is rendered even still plainer when edge of leaf almost becomes inflected.   The (To test the foregoing result I tried the following experiments:

[pencil insertions largely illeg]   after the drops of gum, syrup & starch had been left on 23

[28]

(14

leaves, for the times above specified, & which was more than enough to allow of inflection, I placed on them, without touching them droops of nitrogenous fluids, such as milk, gelatine, urine, albumen; & of the 23 leaves thus treated, 17 had their marginal hairs thoroughly well inflected, & often to edge of the leaf itself;  but the action was slower than when fresh leaves were tried, & only six were not acted on. But the action was slower,  than when these same fluids were placed on fresh fluid leaves, showing that the [illeg] non-nitrogenous fluids having rested on them from 30 to 48 hours had in some degree injured them; & which likewise may [pencil insertion largely illeg]   account for the six not acting having acted.)  

(With respect to the action of nitrogenous fluids tried on fresh leaves & not counting 23 short leaves just referred to when & no others which had been previously experimented on, I made to following trials during September & August & September   in exactly the same manner with the non-nitrogenous fluids;        but I soon saw the same effect [pencil insertion largely illeg]   but did not keep an exact a record of time only in & manner of inflection only in a few cases.  The inflection, however, was always produced in under 24 hours.— 

Milk, tried on 10 leaves caused great inflection in all. I record in one case that the edge of the leaf was much inflected in 5°.—

Urine, tried on eleven 12 leaves, caused great, sometimes extremely great inflection in eleven of them. The times required varied much, I presume partly owing to differences

[29]

(15

In the chemical nature of the urine. I record in two cases that in 17° every marginal thoroughly well inflected, but not to edge of the leaf; in another case after 25°. 30', the terminal edge of leaf most strongly inflected.

At end

Gelatine, isinglass dissolved so as to make solution of two strengths, one as thick as thin cream, & the other thicker, placed on 8 leaves caused all to be inflected. I record in one case that the marginal hairs were thoroughly well inflected in 6° 30', & to edge of the leaf in some degree in 24°.

Albumen. (white of Hen's egg) tried placed on 7 leaves, it caused 6 of them to be well inflected; I record that in one the edge of leaf shape became well inflected in 20°. One of the seven leaves was not acted on in [illeg pencil insertion] for 26°; I then put   was  [illeg pencil insertion]  a drop of milk on this leaf & it was inflected in 12°.—

Fr Cold infusion of raw meat, tried on one leaf alone, in 19° caused much of lea marginal hairs & edge of the leaf to be well inflected.

Mucus; thick from bronchial tubes, caused placed on two leaves caused m inflection. Very think colourless mucus from same source in 5°. 30 caused marginal hairs & edge of leaf to be inflected in 5°. 30', & still more 10 in 20°.—

[30]

(16

Saliva. This is said in Müller's Physiology (Vol I. p. 514) to contain from 1.14. to 1.19 of solid residue; & that this residue yielded 0.25 of ash so that saliva can hardly contain 1 per cent of nitrogenous matter; yet I tested small drops on 8 leaves & they caused inflection in all. I record in one case that after 19°. 30' no great effect was produced, yet all the marginal hairs except 9 were inflected: in a second case a few marginal hairs were inflected in 2°, & in 7° 30' all the marginal hairs at the end of the leaf & the terminal edge of leaf itself was inflected: in a third, all the round-headed marginal hairs were strongly well inflected but not to long-headed hairs.

[illeg pencil insertions]

Seeing the saliva, which contains less than one per cent of animated matter, acted on the leaves I wished to ascertained how little would act, so, I dissolved 4 gr of isinglass in 4 oz of water, which consequently contained & weighed 1 part of gelatin to 437.5 by weight of water. The fluid could not be distinguished in [illeg] from fresh water. I placed left small drops (t (about half a minim) of this solution one some of on seven leaves for 25° & for 41°.   [illeg pencil insertion]   After 18°, four two of these leaves had each 2 or 3 marginal hairs inflected, a third had a few more inflected; & a fourth had the edge of the leaf just perceptibly inflected; so that we here see the action did not [illeg] rather

[See Insectivorous plants, p. 80.]

[31]

(17

Distinguished after the lapse of 6 or 8 hours; & the three other leaves were not in the least affected. So we here have the minimum amount of gelatine action of the which can be recognised not absolutely free from doubt,   & which would be quite overlooked without very careful observation. To I tested two one of the leaves, on which had not acted at all & one which had only two hairs inflected with gelatine as thick as cream & next morning in 16° I found them both strongly inflected.)

Rates of [illeg pencil insertion]

(Hence Altogether I experimented on 49 leaves (not counting the   7 leaves but with that  very weak gelatine) with the above named sum nitrogenised fluids, & only to leaves failed to be inflected; & one of these subsequently acted with milk. But in order to get so large a proportion young & vigorous leaves must be exclusively chosen.)

I should add that I tried two leaves with drops of strong tea, which might contain some nitrogen, but not apparently in sufficient quantity or not in proper state for they did not close.)

Now if we compare this result, with the case of the 38 leaves (not counting those tried with simple water) which did not act with the drops of gum, sugar & other non-nitrogenous fluids; when we remember how large proportion of these same leaves acted when subsequently tested with nitrogenous fluids; & lastly when we remember how differently in what different periods of time the leaves released

[32]

(18

solid substances according to as they contained or did not contain nitrogen, it is impossible to doubt that the leaves of Drosera detected the presence of nitrogen this element; & seeing how largely & ingeniously they catch flies, that they profit by the nitrogenised matter it.   We shall soon see that the [pencil insertion largely illeg]    In making these remarks, I am far from suggesting that no non-nitrogenous subs fluid not containing nitrogen with [2 words illeg], or that all gases   fluids with nitrogen will act; we shall immediately see in the case of mineral certain salts both contingencies occur. I daresay some [illeg] vegetable fluids would probably cause the leaves to become inflected, as well as mechanical actions; but the two or three fluids which I tried, as turpentine, creosote &c killed the leaves.—

Poison          Poison

(The following experiments show the certain salts containing nitrogen cause the inflection of the leaves, but they likewise show that certain other salts & mineral matter fluids likewise cause inflection. These experiment have some interest in showing how such a dose of certain salts is sufficient. But I may have state with respect to all the experiments to be Carbonate of Ammonia

given in this paper, that not foreseeing the results I did not use special precautions for extreme accuracy; nor indeed are these necessary as there is so much difference in the degree of irritability of the different leaves.— I always used distilled water

[33]

(19

& the fluid measure has been tested & corrected & found as correct as the common gradation admits. [2 words illeg]

I weighed accurately but used only a good ordinary druggist balance & weights; & in most cases salt of ordinary purity. I always dropped the fluids onto leaves with the same pointed instrument; not allowing a whole drop to drop off & I repeatedly tested the size of my drops by dripping into a graduated glass & I find that 60 of my drops very nearly equals or is little under 30 minims. [inserted line largely illeg]

Carbonate of Ammonia. Solution of 4 gr to 1 oz produced strongest effect.— Solution of 2 gr to 1 oz tried on three leaves, acted on two.— Solution of 1 grain to 1 oz tried on 12 leaves 10 were well affected, or great many marginal hairs & often to edges of the leaf itself being inflected. But in two or three & ten leaves the drop of solution rolled off & was  a second or third drop was put on which likewise rolled off, yet enough of the salt was absorbed to act.— Two leaves were not at all affected, yet one of these subsequently was acted on by white of egg. (a) The One of the ten leaves reexpanded in 67°; the others in from 21° to 45°, which is much quicker than when flies are caught.— As I put on half a minim, the 8 leaves, which had only one received each a single drop put on alone, received only the 1/960 of a grain of Carbonate of Ammonia.—
How many tentacles to a drop [other pencil insertions not transcribed]

Solution of 1 gr to 1 ½ oz tried on five good leaves,

[33v]

(a)

In two cases in which I recorded the time several hairs became inflected in 35' minutes; in some other cases the movement was much slower.—

[34]

(20

produced no effect; I cannot avoid suspecting that I made some mistake in making the solution. Solutions of 1 grain to 2 oz of water, tried on eleven leaves; five of them were [illeg] decidedly but very slightly inflected, ie from 3 to 6 or 8 extreme marginal hairs being inflected; two of them leaves which I watched reexpanded in 30°; no sensible effect was produced on the other six leaves.

Hence we see the minimum amount of this salt which will occasionally produce a sensible amount of inflection; The & which I should not have trusted, had it not been for the experiments with Nitrate of Ammonia  The quantity of C. of Ammonia with solution of one grain to two oz on each leaf was 1/1920 of a grain.) The – [pencil insertion partly illeg]
Nitrate of Ammonia.— I experimented on 52 leaves with solutions of different strength. of this salt

The leaves are more sensitive to weaker solutions than in the case of the carbonate of ammonia; & this perhaps stands in relation to the salt containing more nitrogen in solut to proportion of 36 to 24 three to two.

Solution of 4 gr to 1 oz or water; tried on six leaves; but this was too strong, causing little inflection & in 24 hours nearly or quite killing four out of the six leaves; yet to my drop contained only 1/240 of a grain of nitrate of ammonia this salt.

Solution 2 g to 1 oz tried on three leaves, in seven hours caused the edges of two leaves & the hairs of the third to be most strongly inflected;  & to have almost more so than I have ever seen.

Each leaf received 1/480 of a grain.—

[35]

(21

Solution 1 gr to 1 oz. tried on three leaves, & [illeg] I found to be all were considerably inflected in after 24 hours. Each leaf received 1/960 of a grain.

Solution of 1 gr. to 1 ½ oz, tried on three leaves, in 16°, one of these was moderately inflected; the other two were hardly at all acted on; no this I but as I subsequently tested these two leaves with albumen & urine & they did not close, they were evidently not in a sensitive condition: I state this fact to show how necessary it is to experiment on several leaves.

Solution of 1 gr to 2 oz; tried on 14 leaves; seven of these were strongly inflected, generally including the edge of the leaf in from 17° to 24°; two were moderately inflected & five not at all. I subsequently tried three of the leaves, which had not closed, with urine, [illeg] & saliva & they were only slightly acted on showing that they were not in a very active leaves condition. Two of the inflective leaves reexpanded in 51°. The nine leaves which were now either so strongly or only moderately acted on [illeg] each. 1/920 of a grain.—

Solution of 1 g to 2 ½ oz, tried on 9 leaves: three of these were greatly affected, the edge of the leaf itself being strongly inflected; five were moderately inflected, ie from 3 or 4 to 6 or 8 extreme marginal hairs being inflected; one alone was not affected, yet was in good state for was subsequently readily acted on by saliva. In the experiment. Chances I had an early form evidently by chance selected by sensitive leaves. In six of the leaves a slight trace of

[36]

(22

action was perceptible in 7°, but full effect was not produced until from 24 to 30 hours had elapsed.

In two cases of the slight inflection the leaves reexpanded in 19°; in the only other case which I observed, viz one which was strongly inflected, the leaf took four days to reexpand — Each leaf received the 1/2400 of a grain of the nitrate of ammonia.—

(Solution of 1 gr to 3 oz or water, tried on 14 leaves.

[bottom of page excised]

[37]

In look at these 52 experiments with the Nitrate of Ammonia, we do not find a perfectly gradation in the diminishing graduated diminution of the effect from the weaker doses solutions; nor could this be expected seeing how much the irritability of the [bottom of page excised]

[38]

(23

leaves vary from age, curling as they have acted before, & as I believe from temperature;

But if we look to the extremes we find a vast difference: the solution of 482 to one oz, though each leaf received only the 1/240 generally killed them: the solution of 1 gr to 2 oz caused acted strongly on half of the leave to be most strongly inflected 14 leaves tried generally causing the inflection of the  generally [illeg]  to solid edge of the leaf & in some cases with of all or nearly all the many marginal hairs. inflected.      yet [illeg] received only 1/1920 of a grain; whereas the solution of 1 gr to 3 oz caused these only on the edges of only two out of 14 leaves to be slightly inflected & three others to have about four 5 or 8 extreme marginal hairs. Nevertheless with respect to this the weakest solution tried, I can entertain no doubt, not that as five leaves were plainly affected & five others very slightly affected, that the effect was really due to the extraordinary single dose of 1/2880 of a grain of the nitrate of ammonia. Some experiments, presently to be recorded will show that still much minuter doses of Carbonate of Ammonia produces a sensible effect on the glands & hairs, though not sufficient to cause their inflection.)

For [illeg] see p. 41 of the same MS.

Acetate of Ammonia (about 4 g to 1 oz of water, I say about because solution was made by dissolving carb. of ammonia in pure acetic acid), tried on two leaves; both were affected in 5°. 30' & in 23° had every single hair strongly inflected. (see p 41.)

[39]

(24

Oxalate of Ammonia solution of 2 gr to 1 oz, tried on two leaves moderately well inflected in 7°; in 23h still more strongly inflected.— Solution of 1 gr to 1 oz, tried on two leaves, (each of which consequently received 1/960 of a grain); one was strongly inflected in 7°, the other not inflected until 30° had elapsed.

[40]

Sulphate of Ammonia 4 gr to 1 oz, tried on three leaves produced no effect in 28°; two of these leaves subsequently tested with milk & albumen because in 2°.45' strongly inflected. Hence it would appear that this salt produced no effect, unless indeed the dose was too strong, which is not probably as the leaves acted so promptly with the milk & albumen.

(Some Error)  so not [illeg]

Sulphate of Ammonia

[41]

(25

Muriate of Ammonia 4 gr to  1 oz, tried on 4 leaves, on three w one had, very few marginal hairs inflected, on the three others no effect was produced; & two of them subsequently tested with milk & albumen were strongly & promptly acted on. Solution of 1 gr to 1 oz tried on two leaves, one both of them in 54° seem [somewhat] injured, but one became fruit inflected. I do hardly knew what to conclude for their experiments.—

Sulphate of Magnesia 2 gr to 1 oz tried on 4 leaves in 48° produced no effect; except on one one, however seems much injured.

Sulp. of Alumina & potash 2 gr to 1 oz tried on 3 leaves in 48° produced no effect, except [illeg] doubtful on one, but they were to experiment was tried too late in season

✓ Chloride of sodium. 2 gr to 1 oz tried on 4 leaves, in 48° no effect on two; a slight & doubtful effect on one a them; but the third fourth in 24° had nearly every hair inflected; this leaf did not begin to reexpand until 4 days had elapsed after the solution was put on; & was hardly perfectly expanded, after sever days had elapsed; so that the salt affected this one leaf in a peculiar manner.

[42]

(26

✓ Nitrate of Soda (not pure as imported from Peru  (4 gr to 1 oz) tried on 3 leaves in 23° almost every hair well inflected & to edge of leaf of one; one leaf, however, seemed subsequently injured. Solution of 2 gr to 1 oz., tried on three leaves, in 7° two were greatly affected ; & in even the edge of leave being slightly inflected; in 24 all three were affected. We may infer from these six experiments the nitrate of soda has a potent effect.

✓ Nitrate of Potash 4 gr to 1 oz tried on 4 leaves, two were much injured, but no contraction in any took place. Solution of 2 gr to 1 oz, tried on 8 leaves; two of them were were slightly injured, two had one single marginal hair inflected, the other six were not in the least contracted after 50°; but two of them appeared somewhat injured. I subsequently tested five of these leaves with milk & gelatine & only one was acted on.— So the nitrate of Potash in these eight trials seems to have no effect.

Nitrate of Lime 2 gr to 1 oz tried on 3 leaves after 30° produced no inflection.

✓ Carbonate of Soda (pure) 2 gr to 1 oz tried on 12 leaves; of these five 7 were became sh well inflected; three others had two or three extreme marginal hairs inflected; & on two alone no effect was produced. But of the seven which were well inflected three were killed by the drop containing the 1/480 of a grain. On the other hand one which was strongly inflected & another which was slightly affected, reexpanded & seemed healthy in 48°.—

[43]

(27

✓ Carbonate of Potash 2 gr to 1 oz, tried on 4 leaves.— Two (Potash not pure) were slightly effected; a third the two others in 48° had many hairs well inflected; which one of these leaves reexpanded after 24° hours. The fourth in 48°, but the other never opened seemed injured & died after five additional days.—

Nitric acid, one minim to 1 oz, barely acidulous to the taste, tried of on 4 leaves; after 24° two of the leaves became moderately well inflected two others not effected & a second dose, put on one of these leaves caused a sensible effect. Two of the leaves seemed injured by the weak nitric acid.—

Dr Nitschke says that weak muriatic & sulphuric acid likewise causes inflection.—

(It is not possible to come to any definite conclusion from these experiments. It would appear that several fluids cause salts cause inflection, but they often suddenly ill the leaves.— We see that the Carbonate, Nitrate, Acetate, oxalate & in lesser degree citrate of Ammonia cause strong inflection; but that the sulphate & muriate are far not at all efficient or in a far lesser degree; this is singular as these two latter salts are known to act as [illeg] when absorbed by the root in earth. It is also remarkable that the non-purified nitrate of soda is more efficient than the nitrate of potash or lime.— The carbonate of soda & potash, though often killing the leaves, plainly cause inflection;

[44]

(28

but we shall hereafter see that these salts produce a different microscopical change in the hairs, to what the salts of Ammonia do.—)

We have seen that the glands are exquisitely sensitive to [illeg] pressure, & minute doses of various matters held in solution: the upper & lower surface of the disc of the leaf is also sensitive to [illeg] pressure; but the back or lower surface of the leaf, owning no doubt to the absence of absorbing glands, is not affected by nitrogenous fluids.         ⸮ yet fly?

For I put left drops of milk, albumen & urine on the backs of five leaves for from 27° & 31° & they produced no effect; & I then put drops of the same fluids on the upper surface & they all became more or less inflected in from 16° to 24°.—)

On the mechanisms of the movement & on the consequent changes in the contents of the cells.— This subject may have been convincingly discussed. When an entire plant is completely submerged under water for 24 hours, the leaves do not become inflected; but Dr. Nitschke states that they can embrace any an object placed on them whilst submerged;    with large drops of water or lin      & this implies that glands go on secreting under water, for ever observation shows that the act of continued secretion & the power of movement go together inflation strictly related.

When, however, a leaf with its footstalk is cut off & left in distilled water from 2 to 3 or 4 hours, 1°.45' to 3° the hairs generally become well & sometimes strongly inflected; as in this case the only difference is that the supply of glands could

[45]

(29

probably continues to secrete, whereas the supply from the absorbent roots is cut off, & as water by itself does not cause any change in the leaves, we have infer that the inflation is in this case due to secretion being in excess of the supply. When the hairs which have thus become inflected & are examined, (& it is necessary advisable to take a young & pale-coloured leaf which has never before acted) the cells on the upper & now concave side of the hairs are no found to be paler-coloured than those on the lower & now convex side : the upper side sometimes is rendered quite colourless   [pencil insertion largely illeg] whilst the lower side is pink; whereas before the [illeg] took place the cells on both sides of the hairs were filled with equally pink fluid. If the leaf be left for several more hours in the water,   when came inflection    (in one two cases 16 & 17   [illeg]  hours about sufficed ; in another case hours sufficed, in others, hours were requisite, another   to produce a effect in a moderate degree  & another hour marked change may be observed in the contents of the side the cells of the hairs pedicels; viz the namely that the contained pink fluid within the which was originally homogeneous, became segregated with colourless fluid & with spherical or, oval or elongated masses of dark red thick [illeg] & apparently viscid matter. Some remarkable The glandular hairs become black from opacity.

In the earlier stages of this act of aggregation some or slight differences can be often be detected be in the contents of the upper or concave sides of the hairs pedicels & the lower sides, namely in the red matter being broken up into smaller masses in the upper side. Remarkable movement in the red matter will presently be described. The terminal glands themselves

[46]

(30

instead of remaining translucent & of a line translucent truly colour, become absolutely black from opacity; & thus does is likewise due to the a process of segregation of the fluid contents of the cells forming the gland into fine granular matter.

(I have selected chosen the case of inflection from simple water, because the changes take place so very slowly & are therefore better to observe. But they are equally well seen if the cut off leaf be submerged in a [3 words illeg] very weak solution of Carbonate of Ammonia, for instance in 15 drops minim of a solution of one grain to 12 ounces of water (ie containing 1/256 of grains) in this case the inflection of the hairs is much stronger; but I have plainly seen the difference in colour in if the cut-off leaf be placed in stronger solutions the act of segregation takes place so quickly that the primary differences in colour on the upper & lower side of the hairs glandular hairs cannot be well seen . The same results follow when drops of nitrogenous fluids, & of certain salts as carbonate of soda, are placed on the growing leaves; & likewise or when any dry organic or inorganic objects is are placed on the centre of the leaf growing leaves.— But that changes with footstalks of the hairs are particularly well exhibited when an atom of hairs or other object any substance thread are is place on at a glands or a single hair single gland; in those such cases I have

[47]

(31

repeatedly seen as soon as the glandular hair had curved half way to the centre a marked difference in the ting of its upper & lowers sides; in two cases this was observed in 1° 10' after an atom weighing only 18 1/35,000 of a grain had been placed on the gland) (in these cases after at atom of thread had been left on for 22° hours on the glands & the footstalk of the gland had been incurved to the centre of the leaf, the prink fluid matter which had been homogenous in all the cells of the footstalk was broken up with numerous minutes spheres spherical, oval & the filament masses, so that I could have easily picked out that glandular hair which had carried the atoms from all the others on the leaf. In one case of the  In these cases, As after 22° hours, the other hairs would naturally have begun to become inflected from the irritation of the atoms some which had been carried to the centre of the leaf; so it was interesting to see might have been expected that the process of segregation just would have commenced in the cells close beneath to glands in all the hairs round the leaf; & this was the case. I tried to initiate [illeg] the effect of slight prolonged pressure, by cutting off a few glandular hairs with with a bit of leaf attached & placing gently pressing them under a compressor; & in 15 minutes, saw the act of segregation take place & plenty of spherical bodies formed in the clear fluid contents of the cells of the glands & of its footstalk

[See Insectivorous plants, p. 42.]

[48]

(32

of the gla just beneath the glands. (a) Finally whatever cause produces well-marked inflection of the hairs glandular hairs after a period ultimately causes segregation of the fluid contents of these cells; even with a common lens the homogenous dark pink colour of an inflected hair can be see to have become mottled.) after inflection.—

(Reflecting on these several facts, more especially on the inflection of a cut-off leaf is submerged in distilled water, & been on the fact of the increased secretion from the glands during the act of inflection, the secreted fluid being slightly pink like the contents of the cells — bearing in mind the change difference of colour which ensues in the upper & lower    & the different degrees of segregation in the cells of     sides of the glandular pedicels hairs ⸮ consequent on the movement,   we may infer that the act of inflection is caused by the act of secretion of the [illeg] fluid pink contents of the cells being more vigorous in the cells on the side which become concave or incurved then on the opposite side which becomes convex. We may further infer that the fluid does probably is not [illeg] secreted from the [illeg] upper cells of the pedicels solely through the gland at the extremity of the hair, but that some of it passes to the adjoining cells on the lower side of the hairs, pedicels which [illeg] then become more distended; for there seems no other way of understanding the marked change of tint which ensues during inflection on the two sides of the hair pedicels, to convex side becoming darker & the concave lighter or quite colourless. It is evidence that in a straight cylinder formed of a multitude of elastic compartments the fl filled with fluid, if

[49]

(a)

It must not be supposed that the act of segregation causes the inflection; for it occurs in the pedicels of the short [illeg] central glandular hairs, when stimulated, which do not bend; & as we shall presently see for the effect of exosmose without any inflection. Nevertheless I have always observed that sooner or later after well-marked inflection, that sooner or later the segregation takes place.

[50]

(33

the fluid be pumped from the compartment on one side to those on the other, the cylinder with bend.

When the inflected hairs begin to reexpand after inflection, the secretion from the terminal glands always ceases; - the period of inflection mainly depending on the, as we have seen, on the glands having become inflected over matter containing nitrogen, which such matter, as we further know, energetically exciting movement. As during reexpansion secretion ceases, & as the roots will go on absorbing moisture, we may infer that the straighteng straightening of the hairs pedicels is due to the cells on the upper & lower sides becoming easily distended with fluid, as in their ordinary condition. As soon as the hairs have become thoroughly expanded, the mottled pink colour, invariably caused by the [illeg] act of segregation of the red matter, disappears, as I have often observed & the cells become again, as I have often observed, filled with homogenous pink fluid.—)

[in margin:] Passing of fluid     May be effect & may be not cause of inflection.—

(That the act of segregations    aggregation,   & of the inflection & the subsequent reexpansion are all connected with the passage of fluid from the cells is likewise shown by the effects of exosmose & endosmose. I cut leaves off nea I placed cut-off leaves in dense groups [illeg], in thick gum, & starch white of eggs & urine & in the causes of a few hours the homogenous pink fluid of within the cells were was broken regulated into colourless fluid with I innumerable spheres of red matter: the leaf in syrup [illeg] became quite flaccid; those in starch & gum were less flaccid had with their hairs very irregularly [illeg]; many of the

[51]

(34

long marginal hairs becoming twisted like a corkscrew. We can As from exosmose to fluid from the cells on both the upper & lower sides of the hairs pedicels would lead to pass into the surrounding dense fluid, we can understand the flaccidity which ensued, in some cases, & the irregular inflection of the others pedicels in other cases. Drops of these same fluids of the case density placed in the disc of growing leaves do not cause inflection; which in no must be owing to the contained supply of water pumped up by the roots to supplying compensating for that lost by exosmose.  

[in margin:] In relation to [illeg] experiment with drops of syrup on back of Leaves.

The leaves which had become in some degree flaccid & irregularly left inflected, when subsequently placed left in distilled water which would be of less specific gravity for from days, because from owing to enosmose nearly reexpanded to a considerable degree & the degree of segregation within the cells because much less. Again I took a leaf with the hairs inflected over a fly & with the contents of the cells much segregated, & placed it in wine; & in the case from the lesser specific gravity of the wine endosmose causes of two hours, several of the hairs reexpanded & others could by a touch be pushed back with their proper expanded places & every trace of segregation had disappeared, the cells being filled with perfectly homogenous pink fluid. (As some of cells in this latter experiment case contained very little segregated red matter, it certainly appears that this matter when [illeg] can pass laterally from cell to cell. From these several experiments we see that we can

[51v]

It would also be a most anomalous [illeg] result; for it would prove show that the plan possessed a power of movement of [words illeg] it; it [words illeg], that from it [remainder not transcribed]

[52]

(35

imperfectly irritate by means of exosmose & endosmose those measurements & change in the contents of the cells, (due to secretion & passage of clud from cell to cell) which takes place in the young plant when excited by either slight mechanical action or by the [illeg] absorption of minuted quantities of nitrogenous & other stimulating fluids.)

Segregation

(When the glandular hairs become inflected from any cause whatever, or when a leaf suffers exosmose from being placed in dense syrup, without the hairs not becoming inflected, the homogenous pink fluid within the cells of the pedicels becomes as already stated we have seen segregated into colourless fluid & dark red, thick & viscid matter, which assumes an infinite variety of shapes. (a)  With wor When a A pale-coloured leaf leaf is exposed on placed in weak solution of Carbonate of Ammonia, this homogenous fluid within the cells of the pedicels of the glandular hair first becomes cloudy, owing to the production, as seen under the highest power of an infinite number of granules, which rapidly coalesce & grow larger: as at first only a few minute spheres are formed & then rapidly grow larger from absorbing matter from the surrounding homogenous fluid. When the segregation, from any cause, takes place in dark-coloured leaf pedicels, the first change generally is that the protoplasm lining the cells shrinks from both ends of the cells, forming over elongated oval mass; this then divides into two or several smaller oval or spherical masses; or perhaps more [illeg] the what large oval mass first becomes internally divided into a multitude of minute spheres, which gradually coalesce into a much fewer larger sphere, & which ultimately separate from each other.

[52v]

(a)

In all ordinary cases of inflection the act of segregation begins close beneath the terminal gland & works down the pedicel.—

[53]

(36

There is [pencil insertion largely illeg]  

It often happens that one group of these small spherical & oval masses becomes aggregated at one end of an elongated cells, & another group at another the other end; & in the act of segregation, as well as during subsequent movements, the red matter gets drawn out into filaments, which when they break, becomes club-headed at their ends.—

[in margin:] These masses [pencil insertion largely illeg]  

These red masses of such infinitely varies shapes floating within the colourless fluid contents of the cells, presents undergoes incessant & curious [illeg]  But these measurements are so slow & gradual, that they might be easily overlooked, [illeg] pedicles of the hairs might often be examined; & get they could escape notice I should not have detected them, had I not made a sketch of the form shape of the red matter in a cell & looking at it again in a couple of minutes I found to my surprise a great change.

I will describe Two cases of the many which I observed will suffice; I cut off a few inflected hairs with a bit of leaf, from a leaf of a dark red leaf which had caught a small moth & placed them in water under the microscope, & selected one cell for observation. The changes which in this case are simple witnessed in the shape of the red matter, [2 words illeg] at intervals of two or three minutes are represent in the accompanying [illeg] diagram of the same cell by figure one to [illeg]   the letters A to H..—

[empty box for sketch] [See Insectivorous plants, pp. 40-41, figs. 7-8.]

See last Paper

As these hairs had been were examined in water, I thought that the changes of form might be due to its absorption. Accordingly I placed a fly on a leaf & in 18 hours when all the hairs were well inflected  & the glands secreting most copiously  I examined

[54]

(37

them in a dry state;  (a)  Selecting a single cell in one of the pedicels, I saw the eight changes in the red matter represented below, take place in about quarter of an hour.

[empty box for sketch] [See Insectivorous plants, pp. 40-41, figs. 7-8.]

This case illustrates all the principal changes; we see the changes of position & of outline, that coalescence of the separate masses & their subsequent redivision; we see the drawing out of strands, & their swelling at separate points so as to take the  form of the a necklace; one of the beds subsequently swelling more than the other. In the former diagram we see one of the most singular changes which frequently occurs; namely the formation of an extremely minute sphere at one end of a larger mass, & its rapid enlargement, in which state it is show at D & E  & its subsequent reabsorption is shown at H F. Sometimes a minute rapidly growing sphere of this kind does not actually touch the larger mass; but as in two cases I discovered with the highest powers & a st a connecting thread thread of the red matter of excessive temerity; such threads probably always occur in these cases as a channel of supply from the larger to the smaller growing mass. As long as I watch for cells any one cell, the slow movements & incessant changes never ceased. X I can compared these The only thing which I have seen like them, are the movement of the sarcode in the protozoa. I saw these currents in the red matter in the

[54v]

(a)

As the fly had been caught for only 18 ours & the glands were secreting most copiously the hairs and would have had no tendency to &c expand & consequently to the red matter to be would not [illeg] have been redfidled for two or three four or five days.

[55]

(38

The pedi short & straight pedicels of the [illeg] in the centre of the disc are coloured filled with green, instead of pink fluid; & I saw similar changes of form in the segregated green matter. I can compared these singular movement only to those of the sarcode in the protozoa.—)

[See Darwin to J. S. Henslow 28 September 1860 in Darwin and Henslow, p. 211.]

(Besides these slow movements changes of form in the red matter, I occasionally, though rarely saw, a conspicuously plain circulation of atoms within the cells & near their walls. Small & variously changed atoms of the red matter were rapidly driven up above to the the longer sides of the cells & more slowly across the short ends & then down, the opposite long side & so round & round The rate of circulation was extremely irregular, & it often ceased. This circulation of the colourless fluid may perhaps account for some other appearances which I saw; namely a struggling movement in a number of small particles of the red matter slightly cohering together & to a large mass of the red matter. Again I have seen a separate filament of red matter, which here & there swelled with beads; & the terminal bead or head slowly swung or wriggled from side to side. It is doubtful whether the circulation of the fluid will account for another appearance, which I several times saw, namely a group of excessively minute atoms, remaining in the same spot, but many [illeg] like a group of living infusoria. It is obvious that the [illeg] will not account for the changes of forms in the red larger masses of red matter; more especially

[pencil insertions not transcribed]

[55v]

(38

Glandular hairs naturally inflated over nitrogenous fluids & flies & over vegetable matter & bits of bits of mass & cinder; & likewise in the red matter segregated from exosmose in a leaf placed in thick gum.— The only I can compare these singular movements only to those of the sarcode in the protozoa.—)

[56]

(39

for the case cases in which a minute sphere appears at the end of a larger mass or in the middle of a filament & rapidly increases in size at the expense of the larger body. We must look at the such changes of form as due to an inherent power of movement in the red matter.    Although the vital action goes over out of    (I cannot hear that anything quite similar to these movement of the red matter has been observed in other plants; but Meyen has briefly noticed them in this case of the Drosera.

We shall hereafter see something analogous in the roots, of other plants exposed to weak solution of Carbonate of Ammonia.—)

Supplement?    [pencil insertion in margin largely illeg]

Details

As such various fluids dropped on the leaves of growing plants causes inflection & after inflection to segregation of the contents of the cells appeared to me worth while to observe the effect & rate of change under the microscope. Accordingly I put fresh cut-off leaves with a little distilled water in a live-box & carefully examined the hairs to see them [4 words illeg]   & then recurring in the water, added minim immediately added from 10 to 15 minims of the following   solutions, & recorded the times of change. The points which I attended to were the blackening of the glands, but more especially the marginal or submarginal hairs; & likewise     & in the interior of cells on which the long-headed marginal of the extreme marginal hairs glands, [illeg]. These latter are particularly fitted for observation, owing to the transparency of the cells.   Water   From [illeg] I examined above a dozen leaves, left in distilled water from 2 to 6 hours & never saw, (except in one doubtful case) any trace of segregation; although, as already stated, the

Segregation in water.

[57]

(40

hairs generally became inflected in from 2 to 3 & differently tinted on their upper & lower sides in from 2 to 3 hours.

[erased pencil insertion illeg]

Carbonate of Ammonia, 3 gr to 1 oz of water, seven young leaves placed on different days in a few drops of this solution were acted on with extraordinary rapidity & energy. In one instance, the gland begins to blacken in ten seconds; (10")   was plainly more darker in 13"; in one minute spherical masses began to form in the couple ben in the cells beneath the oval glands & in the [illeg] beneath the long-headed glands; in 2' the cells of the cushion were almost opake with segregated spheres. In several other cases the act of segregation had travelled down the pedicels from twice or thrice the length of the terminal glands in about 10'.  In the low part of the plant   The action proceeds slower in the lower part of the pedicels; so that it took about 20' from the segregation to reach half-way down the whole length   pedicels   of the long marginal & submarginal glandular hairs    tentacles.— This action invariably commenced in the glands; & all the glandular hairs on the leaf, on an average about 150 or 160 in number were equally affected.  In pale-coloured leaves the first change as seen under a high power is to fluid contents of the cells, close between the glands, is a cloud of granules, which approach each other & form a pear-shaped mass, rapidly grow larger & coalesce. The dark red leaves, the whole content of cells first shrink & then divide into numerous, dark red opake oval & spherical masses.)

[in margin:] already given

It was a curious spectacle to watch under a moderate power, the act of segregation travelling from the glands down the upper parts of pedicels: the process being [illeg] stepped   arranged   at each transverse partition of the own light cells,    & then the contents of each   the    cells below almost flashing ed into a cloudy mass. We shall

[58]

(41

presently see what extremely weak solutions produce more slowly the same results.

Acetate of Ammonia, (about 3 gr to 1 oz): the solutions tried on two leaves excited quite a energetically, & almost as but not quite so quickly as C. of Ammonia. In one specimen, the glands were blackened & signs of segregation were visible in 10'; in 15' the segregation had proceeded down pedicels from the length each that of the glands. In the cushions beneath the long-headed glands, plenty of spheres in abundance were not found, in one case until 39', & in the other, until 54' had elapsed. In 2° the act of segregation had been carried to an extreme extent in all the hairs.

Oxalate of Ammonia (about 3 gr to 1 oz) tried on one leaf: in 24' no marked change; in 47' plenty of spherical masses was formed beneath to oval & long-headed glands glands & from about the length &  these glands & in the [illeg] under the long-headed glands. This amount of action was generally produced by an equally strong solution of C. of Ammonia in from 2' to 5'.—

[bottom of page excised]

[59]

[top of page excised]

Nitrate of Ammonia (3 gr to 1 oz) tried on 2 rather old leaf: in one no marked change produced in 3°.— In the other traces of segregation in 52'; in 1°.22' plain segregation in most of the t beneath most of the glands & in most of the cushions of the long-heads. ; in 2°. 12', as much segregation as from C. of Ammonia in from 5' to 10'.—

This part was tried again of at tried at Eastbourne

[60]

(42

Nitrate Acid (1 minim to 1 oz) tried on two leaves: no marked changes in 1°. I then put one of these leaves in a few drops of the solution of C. of Ammonia (3 gr to 1 oz) & besides a change of tint no conspicuous change was produced in 1°. 18'. I then added a second dose of the C of Ammonia, & in 5' a vast amount of segregation ensued. This experiment is conformable with the [illeg], viz the Nitrate of Ammonia does not act promptly; as this salt would probably have been formed within the cells of the plan from the first dose of the C. of Ammonia.—

✓ Nitrate of Soda & N. of Lime (2 gr to 1 oz); the former produced no plain change in 2°; & the latter none at all in 1° 37'. Yet we have seen that a drop of the N. of soda of same strength placed on growing leaves in the course of several hours causes inflation of the hairs.

✓ Chloride of sodium (2 gr to 1 oz) no effect produced in 2° 5' ; yet a drop of same solution on a growing leaf sometimes causes inflation.

✓ Carbonate of Potash Soda (2 gr to 1 oz). In one leaf no marked change in 1° 5', but I did not attend particularly attend to the state of the gland itself; I then added C. of Ammonia & in 5' a conspicuous amount of segregation was caused. In another specimen, in 50' the long-headed glands had become brown with the content of the cells beginning to aggregate with a few spherical masses; in cells beginning to aggregate with a few spherical masses; in 1° 40' the granular content of the cells seemed almost disintegrated & 2°. 14' the content looked pulpy; many of the cells appeared were almost empty; they too to in the case of the oval glands, similar changes ensued but more slowly. The aggregated few not large aggregated masses within the glands had a wholly different appearance, from that produced by C. of Ammonia; & from that of the glandular hairs naturally inflected over flies.)

[61]

(43

Carbonate of Potash (2 gr to 1 oz). This salt acted like rather more energetically than the last   C. of Soda   causing some slight degree of segregation & in the cells beneath to oval glands in 1° & a conspicuous degree of segregation in 2° 30' [words illeg]   In 1°. 43'  spherical masses began to be formed in the cushions in 2°. 30'.

In 1°. 43' the contents of the long-headed glands had a peculiar appearance; & 2° 30', the same odd, brown, spherical, aggregated masses of granular matter, as described under C of soda, were formed in both the long-headed & oval glands. The exterior & terminal series of cells in three latter oval glands were almost emptied of their contents by the aggregation of the matter in the more central cells of their glands. The appearance presented was very unlike that for C. of Ammonia; & it may be remarked in the experiments with drops of the solutions of C. of Potash & Soda, that though inflection of the hairs were often generally caused by them, the leaves were often suddenly killed.)

(I also tried tried a few animalised fluids, namely white of egg, saliva, milk & urine while we have seen, when dropped on the leaves cause after some hours much inflection. As a preparatory test, I tried moderately thick gum, & no effect was produced in 1°. 45'; the same leaf subsequently tried with the C. of Ammonia much segregation was produced in 5'.— I likewise tried a solution of sugar, 3 gr. to

[62]

(44

three oz (& [illeg] of same strength as the C. of Ammonia always [illeg] in these experiments) & in 4°. 30' no change was produced; then put leaf in the C. of Ammonia & in 5' a great amount of segregation was produced ensued. Saliva produced no effect in 2°. 30'; the leaf tested by C. of Ammonia was strongly acted on in 8°. 10'. Albumen produced no effect in 1° 30'; the same leaf tried in C. of Ammonia was strongly acted on in 5'.— With Milk there was some slight degree of segregation in 1°.— With urine one leaf was most strongly acted on 1° 40' but I omitted to look sooner; another leaf was hardly acted on in 7° 30'; but this was an inactive leaf, for it required 15' for C. of Ammonia to produce decided effect.— I kept some of these same urine for two days & then tried another leaf with it, but [text excised] It would seem from

[in margin:] Here gave raw meat

[bottom of page excised]

[62v]

(All used)