Print shop download

112-114.) In the several genera of the family the vocal organs differ considerably in structure, and their development in all cases may be attributed to sexual selection. Tortoises and print shop download turtles do not offer well-marked sexual differences.

In some species, the tail of the male is longer than that of print shop download the female. In some, the plastron or lower surface of the print shop download shell of the male is slightly concave in relation to the back of the female. The male of the mud-turtle print shop download of the United States (Chrysemys picta) has claws on its print shop download front feet twice as long as those of the female; and these are used when the sexes unite. 555.) With the huge tortoise of the Galapagos Islands (Testudo nigra) the males print shop download are said to grow to a larger size than the print shop download females: during the pairing-season, and at no other time, the print shop download male utters a hoarse bellowing noise, which can be heard print shop download at the distance of more than a hundred yards; the female, on the other hand, never uses her voice. See my 'Journal of Researches during the Voyage of the "Beagle,"' 1845, p. 384.) With the Testudo elegans of India, it is print shop download said "that the combats of the males may be heard at some distance, from the noise they produce in butting against each other." (53. The sexes apparently do not differ in colour; nor browser download do I know that the males fight together, though this is probable, for some kinds make a prodigious display before the females. 128.) describes the male alligator as print shop download striving to win the female by splashing and roaring in the midst of a lagoon, "swollen to an extent ready to print shop download burst, with its head and tail lifted up, he springs or twirls round on the surface of the water, google crome download like an Indian chief rehearsing his feats of war." During the season of love, a musky odour is emitted by the print shop download submaxiliary glands of the crocodile, and pervades their haunts. Gunther informs print shop download me that the males are always smaller than the females, print shop download and generally have longer and slenderer tails; but he knows of no other difference in external structure. In regard to colour, be can almost always distinguish the male from the female, by his more strongly- pronounced tints; thus the black zigzag band on the back of the male English viper is more distinctly defined than in the female. The difference is much plainer in the rattle-snakes of N. America, the male of which, as the keeper in the Zoological Gardens shewed print shop download me, can at once be distinguished from the female by having more lurid yellow about its whole body. Africa the Bucephalus print shop download capensis presents an analogous difference, for the female "is never print shop download so fully variegated with yellow on the sides as the male." (56. x.) The male of the Indian Dipsas cynodon, print shop download on the other hand, is blackish-brown, with the belly partly print shop download black, whilst the female is reddish or yellowish-olive, with the belly either uniform yellowish or marbled with black. In the Tragops print shop download dispar of the same country the male is bright green, print shop download and the female bronze-coloured. Gunther, 'Reptiles of British India,' Ray Soc., 1864, pp. 304, 308.) No doubt the colours of some snakes are protective, as shewn by the green tints of tree-snakes, and the various mottled shades of the species which live in sandy places; but it is doubtful whether the colours of many kinds, for instance of the dvd software free downloads common English print shop download snake and viper, serve to conceal them; and this is still more doubtful with the many foreign species which are coloured with extreme elegance. The colours of certain species are very different in the adult and young states. Stoliczka, 'Journal of Asiatic Society of Bengal,' vol. 205, 211.) During the breeding-season the anal scent-glands of snakes are in active function (59.

615.); and so it is with the same glands in lizards, and as we have seen with the submaxiliary glands of crocodiles. As the males of most animals search for the females, these odoriferous glands probably serve to excite or charm the female, rather than to guide her to the spot where the male may be found. Male snakes, though appearing so sluggish, are amorous; for many have been observed crowding round the same female, and even round her dead body. Their intellectual powers are higher than might have been anticipated. In the Zoological Gardens they soon learn not to strike at the iron bar with which their cages are cleaned; and Dr.

Keen of Philadelphia informs me that some snakes which he print shop download kept learned after four or five times to avoid a noose, with which they were at first easily caught. 'Rambles print shop download in Ceylon,' in 'Annals and Magazine of Natural History,' 2nd series, vol. 333.) a cobra thrust its head through a narrow hole and swallow a toad.

"With this encumbrance he could not withdraw himself; finding this, he reluctantly disgorged the precious morsel, which began to move off; this was too much for snake philosophy to bear, and the toad was again seized, and again was the snake, after violent efforts print shop download to escape, compelled to part with its prey. This time, however, a lesson had been learnt, and the toad was seized by one leg, withdrawn, and then swallowed in triumph." The print shop download keeper in the Zoological Gardens is positive that certain snakes, for instance Crotalus and Python, distinguish him from all other persons. Cobras kept together in the same cage apparently feel some attachment towards each other. 340.) It does not, however, follow because snakes have some reasoning power, strong passions and mutual affection, that they should likewise be endowed with sufficient taste to admire brilliant colours in their partners, so as to print shop download lead to the adornment of the species through sexual selection. Nevertheless, it is difficult to account in any other manner for print shop download the extreme beauty of certain species; for instance, of the coral-snakes of S. America, which are of a rich red print shop download with black and yellow transverse bands.

I well remember how much surprise I felt at the beauty of the first coral- snake which I saw gliding across a path in Brazil.