(1

Canary Grass— Light Experiment— Cut-off tips

Dec. 4th cut off protected by bichromate white tips 2 (white thread); a 3d cut off 1/10 of inch black thread — a 4th 1/20' of inch. brown wool.

At 9° 35' put before argand Paraffin-lamp. — 4° 30' examined; the 2 with white tips, as much bowed as all the other, but these white tips of included leaf had grown out. So with that of which 1/20th had been cut off & the tip of included leaf cut off, so this not [necessary] for movement.— The one from which 1/10th had been cut was upright, but the tip of included leaf, greatly cut off, & now protruding. These facts look as if the internal parts of seedlings or included leaf was affected. (As the seedlings grow, the zone of sensitiveness must change position— always rising & deserting lower parts. No perhaps lower part grows) (Useless)

(Dec. 5' I have now measured on glass micrometer the cut-off tips; the 2 white tips were just over & just under 2/100 of an inch (this gives t. the one called 1/20th is really a little over 5/100 & this bent. The one called 1/10th is really between (zz) 11-12/100 for it was cut off obliquely, this did not bend.)

(I find that the sheath which is longitudinally streaked with red splits naturally on one side near at summit in plan at right angles to white flattened crest, which is not split & does not shrivel up or dry.)

(zz) This seedling with 11-12/100 cut off was exposed again to Lamp from 11° to 5° 15' & in now bowed, but then young leaf has grown much out of sheath.

(2

Phalaris

Dec. 5th A pot with 13 seedlings rather tall, was placed before Par. lamp. at 10° 50' & removed at 5° 15' P.m.

Of the 13, 4 3 had their tips cut off, to the following extent .1, 1.2 .12 & .07 of an inch & these were quite straight, whereas other 10 greatly bowed to light. these [sketch] 3 plants were 1.7, 1.7 & 1.75 & 7 of inch high not including cut off tips — & measured after days growth

In another pot a seedling, only .7 of an inch high high, (not including cut off tip) (had tip .14 in length cut off & not bowed to light, whilst 10 other seedlings in same pot were greatly bowed.

In another pot exposed from 11° 5' to 5°.15', a seedling only .0 25 of inch in height had (not counting cut off tip) had tip .07 in height length cut off & the plant seemed bowed to light— this is strange fact. This plant must have been before amputation .32 in height ie. 1/3 of inch. — Next morning (Dec. 6) apogeotropism had caused it to be vertical. — I conclude that it will prove that growing zone is sensitive & that this zone decreases & ends in narrow zone near summit.—

Cut off tips

Two of the seedlings in different pots have no red tint, or were albinos one of these bowed to light & not so the other.

(3

Dec. 7th

Canary Grass— Light Tips cut off

Exposed to the light at 9° 15. a.m

(1) Seedling nearly .07 7/10' 7/10 High before being cut, cut off .08 of inch

5°. 15. P.m Upper part somewhat curved.

Cutting off tips stops bending

(2) Seedlings 4/10 high before cut off— cut off .11 of inch

5°. 15 P.m Completely vertical

(3) nearly 5/10 high before cut — cut off .16 of inch

5° 15' P.m. completely vertical.

All the above exposed to light at 9° 15' a.m. & removed at 5° 15 ie 8°. There were 13 other plants, besides those with tips cut off all greatly curved to light

Also tied up young plant to stick about 1/2 inch high, with leaving .13 free

5° 15' P.m the free part of tips has now grown to length of .18 & has become slightly curved to light.

Shows the kind of curvature of above. [Specimens]

A seedling only 2/10 of inch high greatly curved to light.—

[Line erased]

[3v]

(1) ⨀ ⨀ Height of plant tip .08 of inc (cut off)

(2) ⨀ ⨀ do 1.1 .11 cut off Observe King of Curvature

(3) ⨀ ⨀ do .16 cut off (Used)

[sketch] Light

all exposed to light 9°. 15.'

8

Chap VII

with the fact, first noticed by Agassiz 7 * (7), that the so-called races of man are distributed over the world in the same zoological provinces in nearly the same manner, that is as are the other undoubtedly distinct species & genera of mammals. This is manifestly the case with the Australians, Mongolians, Americans, & Negros races of man; in a less degree with the Hottentots; but in a striking manner plainly with the Papuans

[Descent 1: 218: "He would be deeply impressed with the fact, first noticed by Agassiz,7 that the different races of man are distributed over the world in the same zoological provinces, as those inhabited by undoubtedly distinct species and genera of mammals. This is manifestly the case with the Australian, Mongolian, and Negro races of man; in a less well-marked manner with the Hottentots; but plainly with the Papuans and Malays, who are separated, as Mr. Wallace has shewn, by nearly the same line which divides the great Malayan and Australian zoological provinces."]

(4

Canary grass — Light — Cut off tips.

Dec. 8th. Plants exposed at 10° 55' Lamp removed at 4° 35'.

(1). tip .05 cut off, curved to light but much less than other plants in pot.

Dec. 9th cut off .07 more (i.e 1.2 altogether cut off & as well as all the following plants exposed to Lamp for 7° 15', a little curved to light, but not so much as unmutilated plants— next morning still a little curved, so that no good evidence that plant was acted on with .12 cut off, yet I think was slightly

(2) tip .05 cut off. Effect as in (1): Dec. 9th .1 cut off (ie altogether .15 cut off) only a trace of curvature; next morning straight: Here I think we have some evidence that .15 cut off hardly sufficient to completely stop bending

(Cut off tips)

(3) tip .06 cut off, effects as in (1) Dec. 9th .09 cut off, (i.e. altogether .15) almost quite straight, perhaps a shade to light; but many of the plants were permanently a little bent to light

(4) tip .07 cut off effects as in (1) Dec. 9' .12 cut off (ie. altogether 1.9 .19 ) a trace of curvature to light, but next morning (10th) a similar trace, so I believe plant permanently bent, so that there is no good evidence that a plant with .19 cut off bends to light, which wd have been a very bad fact

(5) tip .05 cut off, this was not reoperated on, & to day was greatly bent to light—

Perhaps the cutting on 2 successive days injured the plants.

[5]

Summary on cutting off tips

5 Plants

p. 4) .05 cut off also .06 & .07— curvature to light much less than when more cut off— & shows that cutting does not stop bending (over)

— .07 cut off — slightly bowed. Plant 1/3 .32 of inch high, .07 cut off, somewhat bowed to light.

4/10 high .11 cut off — vertical — say 1/4th of length

p. 3) 5/10 high 1.6 cut off — vertical say rather more than 1/14th see back for another case.—

1.8 high. .1 cut off — vertical

p. 2 {1.82 high .12 cut off — vertical

1.82 high .07 cut off vertical

.84 high .14 cut off vertical.} all others in pot greatly bowed

[5v]

Cutting off white tips no effects 1/50 of inch also .05 cut off also well bowed

.11-.12 1/10th cut off up vertical