(1

(Although there can be no doubt that the direction & degree of illumination of the upper part of the cotyledon affects greatly the curvature of the lower part, yet the following some observations, made it highly probable show that the identica l similar— similar stimulation illumination of the latter lower part viz from by light greatly favour or greatly favour or is almost necessary for its curvature; but our experiments were not for several reasons conclusive, owing to the difficulty of excluding light from the lower half, with simultaneously preventing its curvature.

(or yet the curvature curvature in this part almost require & is greatly favour by its— simultaneous illumination )

(M.S. Perhaps to be used)*?

Thus Blackened glass tube was slipped over 8 Cots, so as to rest on the sand protect the basal half halves from the light, the upper part halves half being fully illuminated— now it might have been expected that these would have acted on would have become well curved to the light on the lower halves & caused them to bend to the light through action of the upper part half; but only one was well bowed, 4 slightly & 3 remained upright. The glass tube, however, which rested on the sand must have offered some mechanical resistance to curvature for 8 other coty were similarly enclosed in unpainted glass tube, & only half of them became incline to the light.— In the next place 14 the upper halves of 14 fort fourteen. Cots were painted all round with Indian ink, & 12 of them remained all day

51

Chap. 17 18 Mammals – Colour.

fully developed. In the male of that magnificent strepsiceros antelope, the Oreas or Boselaphus Derbianus, the body of the male is redder, the whole neck much blacker; and the white band which separates these colours, broader, than in the female.

In the other a second species of the same genus the male is slightly darker than the female (a) and the young of both sexes redder than in the either adults sex. 25 * (45)

Turning now to the

the male of In the the A. Bezoartica which belongs to another tribe of antelopes the male is very dark, almost black; whilst the hornless female is fawn-coloured, and we have have in this species as Mr. Blyth informs me, an exactly parallel series of facts, as with the Portax picta, namely in the male periodically changing of colour in the male being seasonal during the breeding season, in the effects of emasculation on this change, and in the young of bother sexes being undistinguishable. In this [words excised]

[Descent 2: 288-9: "With most or all of the highly-ornamented species of Tragelaphus the males are darker than the hornless females, and their crests of hair are more fully developed. In the male of that magnificent antelope, the Derbyan Eland, the body is redder, the whole neck much blacker, and the white band which separates these colours, broader, than in the female. In the Cape Eland also, the male is slightly darker than the female.25
In the Indian Black-buck (A. bezoartica), which belongs to another tribe of antelopes, the male is very dark, almost black; whilst the hornless female is fawn-coloured. We have in this species, as Mr. Blyth informs me, an exactly parallel series of facts, as with the Portax picta, namely in the male periodically changing colour during the breeding season, in the effects of emasculation on this change, and in the young of both sexes being undistinguishable from each other."
25 Dr. Gray, 'Cat. of Mamm. in Brit. Mus.' part iii. 1852, p. 134-142; also Dr. Gray, 'Gleanings from the Menagerie of Knowsley,' in which there is a splendid drawing of the Oreas derbianus: see the text on Tragelaphus. For the Cape Eland (Oreas canna), see Andrew Smith, 'Zoology of S. Africa,' pl. 41 and 42. There are also many of these antelopes in the Zoological Society's Gardens.]

(2

as might have been expected upright when exposed to a lateral light & 2 become very slight curved. Thirteen other Cots had very thin, lower halves painted all round & this part remained vertical, whilst the upper illuminated half, became in all the same excepting one curved more or less towards the light; yet the upper part was not able to affect the lower— transmit any affect cause the lower when not illuminated parts to bend; but then here we have the doubt whether the crust of paint did not mechanically prevent the bending of the lower part or injure the it. Lastly the lower half halves of 7 Cots were enclosed in g. B. Gold-beaters' skin which is f flexible & transparent & 5 of these became well curved to the light, the basal part of 2 remaining almost straight. The lower halves of Twelve other cots were similarly enveloped in gold. B skin, but this was painted thickly with Indian ink; & no now the bases of 8 remained upright & of 4 become slightly curved to the light; but it is poss shd be remarked observed that thickly painting the g. B skin gold-beaters skin cd [render] it more more rigid.

[130v]

Chap. 17 18 Mammals – Hair.

of the forehead in the males of several breeds of sheep, the mane in the ram of an African breed, and lastly the presence of a mane, long hairs on the hinder thighs and a dewlap in the male alone of the Berbura goat 18 *(40) (a) text

II (although we ought to be extremely cautious, in concluding as shown in my work on Variation under Domestication, in concluding that any character, even with animals kept by semi-civilised people, has not been subjected to man's selection & thus augmented; yet this is not probable with the characters in the cases, just specified more especially as the characters which are either confined to the males, or are more strongly developed in them than in the females. If it were positively known that the maned African ram was descended from the same primitive stock as the other with all the other common breeds of sheep, or the Berbura male goat with his mane, dewlap, &c, from the same stock as with other goats; and if selection has not been steadily applied to these characters, then they must be due to simple variability together with the law of sexually limited inheritance, and we ought perhaps In this case it would be the best to extend the same conclusion to every all the many analogous cases with characters occuring in animals in a state of nature. Nevertheless I can hardly persuade myself that this is the origin of the extraordinary development of hair on the throat and fore-legs of the male Ammotragus or of the immense beard of the male Pithecia, & some other such cases. simply have thus arisen.

With those antelopes in which, as we shall presently see,

[Descent 2: 284-6.]

(3

(Many trials were made by painting the Cots. of Pl. with Indian thick. It is not probable that we have good reason to believe that they were not soon injured by the exclusion of air, but the layer of Indian ink, when not thick was apt to crack & admit light, & when very thick the crust thus formed sometime pre rendered curvature difficult or impossible.

(Perhaps what follows had better come in after effects of gold-beaters skin at base)

(Abstract Used)

Nevertheless the following cases well deserve notice 14 se cots had upper half & 14 13 had lower half painted with Indian ink, & the pots were placed during the day before S.W. window. Those with upper half painted remained quite upright, or showed in 2 cases a mere vestige of curvature toward light, yet we must remember that the lower half, which is the part which become most curved, were fully exposed to light during whole day. They presented wonderful contrast with the seedlings altogether unpainted, many of which were bowed to ground. Of the 13 with the lower parts painted, this part remained vertical, whereas the upper unpainted part became in all the cases (except 1) curved towards the light though sometimes only slightly. Therefore we see that the painting exclusion of the light from the upper half by being painted with Indian ink stops the bending of the lower & illuminated part; whereas the exclusion of light from the lower part does not stop the bending of the upper illuminated part, though it does stop the bending of the lower & coloured darkened part.

We may must therefore conclude that when upper part is illuminated it transmits some effect to lower part as causing it to bend, if it is itself at the time illuminated; but that the lower part transmits no such effect to upper part.

[in margin:] In all these cases a wonderful contrast between those with upper & lower halves painted & with free seedlings in pot

Then give gold-Beaters skin

(70A

Ch 17 18 Mammals

Mr. Bartlett, in which the face is strongly coloured in the adults animal of both sexes, that colouring are quite dull or absent, or not at all bright during early youth. This is likewise the case with the mandrill & Rhesus, in which species the brilliant colours on the face & posterior end of the body are developed only in one sex alone when adult; we have therefore, every reason to believe that the colours of the skin in these two species have been acquired by other two species through sexual selection, & we are naturally led to extend the same view to the foregoing species, though both adult sexes have their faces coloured with equal brightness.)

[Descent 2: 310: "In all the species known to Mr. Bartlett, in which the adults of both sexes have strongly-coloured faces, the colours are dull or absent during early youth. This likewise holds good with the Mandrill and Rhesus, in which the face and the posterior parts of the body are brilliantly coloured in one sex alone. In these latter cases we have every reason to believe that the colours were acquired through sexual selection; and we are naturally led to extend the same view to the foregoing species, though both sexes when adult have their faces coloured in the same manner."]

(4

Tin-Pipes

(Trials with little caps or pipe made of extremely thin tin-foil, closed at the upper ends were more trustworthy; but these were sometime rather too heavy, though made of excessively thin tin-foil— & light sometimes entered below, when the pipes did not fit closely & to prevent this the pipe was pinched lightly, but there was risk of being too much pinched. This source Whether of error was avoided by ever this cause was ascertained in several case by removing the caps & exposing the Cots to light, & as they then became well bent to light clearly not injured— To reduce the admission of light at base of pipe black paper was placed on soil round bases of Cotyledons. — The seedling exposed sometimes to SW. window,— sometimes Paraffin Lamp.

Abstract of Results First — Abstract

p. 1. exposed for 8° 30' 3 seedlings — from 6/10 to 7/10 high all pointed to light (window) but bases not nearly so much bent as the 13 other plants in pots.— Depth of Caps not stated. — & those with Caps became bent much more slowly for after 5° quite vertical.

(As depth of caps not Known Omit?)

p. 2. (4 with Caps) all vertical

exposed to SW. window for 6° 45'; 4 seedlings, (height not given) with caps varying in depth from .15 to .19 not affected by light, whereas 8 other seedlings with in same pot were all greatly bent down to near especially near bases. Next day these 4 seedlings had caps removed & exposed for 6°. 45' to Paraffin lamp, & all became well curved to light, showing that they had not been injured by light

4 Tested with lamp

[slip of fragment]

75

[w]hiskers &

observe

always

70

Ch 17 18 Mammals – Colour

with a large naked spot on the forehead of a bluish-white colour, and a long black beard. The face of Macacus lasiotus is its dirty-flesh-coloured has two with a defined red spots on each side of cheek. face. The appearance of Cercocebus æthiops is most grotesque with its black face, white whiskers and collar, chestnut head and two a large naked white spots over the two each eyelids. (a) (text) The whole face of a S. american Brachyurus calvus is of a "glowing scarlet hue; but this colour does not appear until the animal is nearly mature. *(62) as this colour does not appear thill near maturity, and as we know that bright red naked skin is often a sexual character with monkeys, we may here more confidently believe that this hue has been acquired through sexual selection. It is curious how greatly the skin of the face differs in colour in different monkeys the various species: it the skin is often as black as that of the most sooty negro, passing into brown and flesh-colour, with parts perfectly white; we have, as just soon, a in the Brachyurus, [illeg] it's the scarlet tint, is higher than that of that of in the most blushing Caucasian damsel; sometimes the skin is it is more distinctly orange­-coloured, than in any Mongolian; and in several monkeys it is of a most decided blue, pasing into violet or grey. The beard, whiskers and other tufts of hair are very commonly of a different colour from the rest of the head, being often pure white, and In all the species, known to

[Descent 2: 308-9: "The Semnopithecus frontatus likewise, has a blackish face with a long black beard, and a large naked spot on the forehead of a bluish-white colour. The face of Macacus lasiotus is dirty flesh-coloured, with a defined red spot on each cheek. The appearance of Cercocebus æthiops is grotesque, with its black face, white whiskers and collar, chesnut head, and a large naked white spot over each eyelid. In very many species, the beard, whiskers, and crests of hair round the face are of a different colour from the rest of the head, and when different, are always of a lighter tint,44 being often pure white, sometimes bright yellow, or reddish. The whole face of the South American Brachyurus calvus is of a "glowing scarlet hue;" but this colour does not appear until the animal is nearly mature.45 The naked skin of the face differs wonderfully in colour in the various species. It is often brown or flesh-colour, with parts perfectly white, and often as black as that of the most sooty negro. In the Brachyurus the scarlet tint is brighter than that of the most blushing Caucasian damsel. It is sometimes more distinctly orange than in any Mongolian, and in several species it is blue, passing into violet or grey. In all the species known to Mr. Bartlett, in which the adults of both sexes have strongly-coloured faces, the colours are dull or absent during early youth. This likewise holds good with the Mandrill and Rhesus, in which the face and the posterior parts of the body are brilliantly coloured in one sex alone. In these latter cases we have every reason to believe that the colours were acquired through sexual selection; and we are naturally led to extend the same view to the foregoing species, though both sexes when adult have their faces coloured in the same manner.
44 I observed this fact in the Zoological Gardens; and numerous cases may be seen in the coloured plates in Geoffroy St.-Hilaire and F. Cuvier, 'Hist. Nat. des Mammifères,' tom. i. 1824."]

(5

Tin Pipes

p. 3. (4 caps vertical) — 4 exposed to paraffin L on level with pot for 6° 30'— seedling young about 4/10 of inch— some very little some higher & some little shorter.

(1) cap. internally .1 deep. vertical O

(2) — .15 — do ✓

(3) — .15 — do ✓

(4) — .08. do O

(5) cap. only .07 deep— seedling only .31 high, exposed for 7° was slightly curved to light. O

(2 Tested by reversing Caps)

on next day caps removed & pot again exposed to Lamp & all 4 greatly bent to light

(A) There were 13 other plants in pots all wonderfully bowed to light so that upper part almost horizontal

(B) (p. 6) exposed Lamp for 7° 45' — deep caps too Heavy — plants already curved

(1) Pl. .8 high, cap .1 deep. much curved to light— did not become vertical during following night— so weight or injured

(2) Pl. .95 high cap .25 deep. — slightly curved to light— became vertical during night.— Anomaly X

(3) Pl. .75 height — Cap. .2 deep very considerably curved to light— remained during night, as much curved as ever.

(4) Pl. .9 height— Cap .19 deep. Vertical ✓ (5)

(C) p. 7. Exposed S.W window for 7° 40'

(1) Pl.1 inch high, Cap. heavy .1 deep. — slightly curved to L.

(2) — .8 cap heavy .25 deep X — do. Anomaly X

(3) — 1.15 —.2 vertical ✓ (6)

(4) — 1.05 heavy — .19 very slight curved 5 ✓

(5) — 1.05 light .1 — slightly curved O

(6) .8 high —.19 vertical ✓ (7)

(7) 1.1          — .19. vertical (8)

(8) .9 .13 vertical (9)

(9) 1.1          — .15 .06 very considerably curved, but rather laterally— weight. O

(10) .8 .2 ✓ slightly curved but next day reversed very considerably curved, so I suppose weight.

After the 7° 40' of exposure great contrast in curve between these 10 seedlings & the many other in the pots. which were expos to light at same time.—

69

Chap. 17 18 Mammals – Colour

as well as in the development of the beard, whiskers, and and mane as canine teeth, size & strength. Many species are coloured either in so extraordinary or in so beautiful a manner and are furnished with such curious & elegant crests of hair, that we can hardly avoid looking at their colours and at the varied tufts or crests of hair characters as having been gained for the sake of ornament, for It is scarcely conceivable that such these strongly contrasted colours and elegant tufts crests of hair can be the have be the results of for of mere variability without the aid od selection; and it is inconceivable that they can bear have be of any direct ordinary use to these animals.

[in margin: Figs nos of Heads of Monkeys]

Id so, it is highly probable that these ornaments have probably been gained through sexual selection, and having been transmitted in most cases transmitted equally or nearly almost equally to both sexes.

In the greater size and strength (a text) of the body in the males of many kinds of monkeys and in the greater development of their canine teeth, in the males of many kinds of monkeys comparison with the females we have other additional evidence of the action of sexual selection.) II I will now give (a few instances, and almost any number could be added, firstly, may here be given, of the strange manner in which both sexes of some species are coloured, and secondly of the beauty of others species.

The face of the Cercopithecus petaurista is black, with white the whiskers and beard and being white with a defined, round, white spot on the nose, covered with short white hair; on the nose, which & thus gives it to the animal an almost ludicrous aspect. The Semnopithecus frontatus, [(Fig 75) also likewise has a blackish face,

[Descent 2: 306-8: "Quadrumana.—Before we conclude, it will be advisable to add a few remarks to those already given on the ornamental characters of monkeys. In most of the species the sexes resemble each other in colour, but in some, as we have seen, the males differ from the females, especially in the colour of the naked parts of the skin, in the development of the beard, whiskers, and mane. Many species are coloured either in so extraordinary or beautiful a manner, and are furnished with such curious and elegant crests of hair, that we can hardly avoid looking at these characters as having been gained for the sake of ornament. The accompanying figures (figs. 70 to 74) serve to shew the arrangement of the hair on the face and head in several species. It is scarcely conceivable that these crests of hair and the strongly-contrasted colours of the fur and skin can be the result of mere variability without the aid of selection; and it is inconceivable that they can be of any ordinary use to these animals. If so, they have probably been gained through sexual selection, though transmitted equally, or almost equally, to both sexes. With many of the Quadrumana, we have additional evidence of the action of sexual selection in the greater size and strength of the males, and in the greater development of their canine teeth, in comparison with the females.
With respect to the strange manner in which both sexes of some species are coloured, and of the beauty of others, a few instances will suffice. The face of the Cercopithecus petaurista (fig. 75) is black, the whiskers and beard being white, with a defined, round, white spot on the nose, covered with short white hair, which gives to the animal an almost ludicrous aspect. The Semnopithecus frontatus likewise, has a blackish face with a long black beard, and a large naked spot on the forehead of a bluish-white colour. The face of Macacus lasiotus is dirty flesh-coloured, with a defined red spot on each cheek."]

(6

Caps of Tin Foil

p. 8. exposed for 7° 30' to Lamp. 1

(1) cap .2 deep vertical ✓

(2) —.17 — vertical ✓

(3) .2✓ vertical with respect to light, but bent at right angles & remained bent all night. (?)

(4) .18          ✓

(5) .12 slightly curved & rather obliquely, & so remained all night O

(6) .16 ✓ slightly curved to light, & much curved laterally, tubes not well closed at base.

(7) .2—— quite vertical ✓

(8) .1 somewhat curved to light , but not nearly so much as other seedling in pot— next morning was upright O

(9) .2 quite vertical.

p. 5. Different Plan— an attempt to ascertain how much of tip sensitive. — pipe of Tin-foil — slipped down. — so as to expose tips for given length & basal part (see description & length of exposure how Effected.) & for result —at I may say by glass-pipes about .2 of inch in length— I must say length of pipes forgot to be recorded accurately— but more of base of tip exposed.—

This of importance when I know zone of chef growth. —

I think it will be proved that the illumination of the upper .2 of cotyledons is the regular portion— & this not course of upper 1/3 or 1/4 of plant— & I doubt whether this chief zone of growth.—

73

(68

Chap. 17 18 Mammals – Colour.

young should not have been equally protected, and it is still stranger in the case of certain adult deer, that the spots should have disappeared exclusively or chiefly during the breeding season. This latter fact raises the suspicion that the general colour of the body has been modified through sexual selection: and in the case of domestic asses we know that when they vary in a certain manner in colour, viz, when they become grey or reddish-brown, the shoulder and often the spinal stripes disappear. *(60) Our ignorance however of the cause of the disappearance of coloured stripes is well shown by a remark made by Mr. Sclater, namely that the species of Asinus which inhabit the Asiatic continent are quite destitute of stripes, have not having been the cross shoulder-stripe; whist those which inhabit Africa are conspicuously striped; over a large part of the body with the exception of A. tæniopus, however, must be excepted for this African which inhabits the almost intermediate country of Abyssinia, and this species has the cross shoulder-stripe and as well as faint bars on the legs, *(61) but it inhabits the almost intermediate regions of Upper Egypt & Abyssinia.) *(61)

(A few observations Before we conclude, a few remarks must be added on Monkeys. In which the young most of the species the sexes generally resemble each other in colour, in colour but in some of which, as we have seen, the male species, the males differs in colour from the females, especially in the naked parts of the skin,

[Descent 2: 305-7: "This may be the true explanation, but it is rather strange that the young should not have been equally well protected, and still more strange that with some species the adults should have retained their spots, either partially or completely, during part of the year. We know, though we cannot explain the cause, that when the domestic ass varies and becomes reddish-brown, grey or black, the stripes on the shoulders and even on the spine frequently disappear. Very few horses, except dun-coloured kinds, exhibit stripes on any part of their bodies, yet we have good reason to believe that the aboriginal horse was striped on the legs and spine, and probably on the shoulders.42 Hence the disappearance of the spots and stripes in our adult existing deer, pigs, and tapirs, may be due to a change in the general colour of their coats; but whether this change was effected through sexual or natural selection, or was due to the direct action of the conditions of life, or some other unknown cause, it is impossible to decide. An observation made by Mr. Sclater well illustrates our ignorance of the laws which regulate the appearance and disappearance of stripes; the species of Asinus which inhabit the Asiatic continent are destitute of stripes, not having even the cross shoulder-stripe, whilst those which inhabit Africa are conspicuously striped, with the partial exception of A. tæniopus, which has only the cross shoulder-stripe and generally some faint bars on the legs; and this species inhabits the almost intermediate region of Upper Egypt and Abyssinia.43
Quadrumana.—Before we conclude, it will be advisable to add a few remarks to those already given on the ornamental characters of monkeys. In most of the species the sexes resemble each other in colour, but in some, as we have seen, the males differ from the females, especially in the colour of the naked parts of the skin, in the development of the beard, whiskers, and mane."
42 'The Variation of Animals and Plants under Domestication,' 1868, vol. i. p. 61-64.
43 'Proc. Zool. Soc.' 1862, p. 164. See, also, Dr. Hartmann, ' Ann. d. Landw.' Bd. xliii. s. 222. ]