The Expression of Emotion in Man and Animals [44]
besides hissing. Many years ago I observed in South America that a venomous Trigonocephalus, when disturbed, rapidly vibrated the end of its tail, which striking against the dry grass and twigs produced a rattling noise that could be distinctly heard at the distance of six feet.[25] The deadly and fierce _Echis carinata_ of India produces "a curious prolonged, almost hissing sound in a very different manner, namely by rubbing "the sides of the folds of its body against each other," whilst the head remains in almost the same position. The scales on the sides, and not on other parts of the body, are strongly keeled, with the keels toothed like a saw; and as the coiled-up animal rubs its sides together, these grate against each other.[26] Lastly, we have the well-known case of the Rattle-snake. He who has merely shaken the rattle of a dead snake, can form no just idea of the sound produced by the living animal. Professor Shaler states that it is indistinguishable from that made by the male of a large Cicada (an Homopterous insect), which inhabits the same district.[27] In the Zoological Gardens, when the rattle-snakes and puff-adders were greatly excited at the same time, I was much struck at the similarity of the sound produced by them; and although that made by the rattle-snake is louder and shriller than the hissing of the puff-adder, yet when standing at some yards distance I could scarcely distinguish the two. For whatever purpose the sound is produced by the one species, I can hardly doubt that it serves for the same purpose in the other species; and I conclude from the threatening gestures made at the same time by many snakes, that their hissing,--the rattling of the rattle-snake and of the tail of the Trigonocephalus,--the grating of the scales of the Echis,--and the dilatation of the hood of the Cobra,-- all subserve the same end, namely, to make them appear terrible to their enemies.[28]
[24] Mr. J. Mansel Weale, `Nature,' April 27, 1871, p. 508.
[25] `Journal of Researches during the Voyage of the "Beagle," ' 1845, p. 96. I have compared the rattling thus produced with that of the Rattle-snake.
[26] See the account by Dr. Anderson, Proc. Zool. Soc. 1871, p. 196.
[27] The `American Naturalist,' Jan. 1872, p. 32. I regret that I cannot follow Prof. Shaler in believing that the rattle has been developed, by the aid of natural selection, for the sake of producing sounds which deceive and attract birds, so that they may serve as prey to the snake.
It seems at first a probable conclusion that venomous snakes, such as the foregoing, from being already so well defended by their poison-fangs, would never be attacked by any enemy; and consequently would have
{note [27] continued} I do not, however, wish to doubt that the sounds may occasionally subserve this end. But the conclusion at which I have arrived, viz. that the rattling serves as a warning to would-be devourers, appears to me much more probable, as it connects together various classes of facts. If this snake had acquired its rattle and the habit of rattling, for the sake of attracting prey, it does not seem probable that it would have invariably used its instrument when angered or disturbed. Prof. Shaler takes nearly the same view as I do of the manner of development of the rattle; and I have always held this opinion since observing the Trigonocephalus in South America.
[28] From the accounts lately collected, and given in the `Journal of the Linnean Society,' by Airs. Barber, on the habits of the snakes of South Africa; and from the accounts published by several writers, for instance by Lawson, of the rattle-snake in North America,--it does not seem improbable that the terrific appearance of snakes and the sounds produced by them, may likewise serve in procuring prey, by paralysing, or as it is sometimes called fascinating, the smaller animals. no need to excite additional terror. But this is far from being the case, for they are largely preyed on in all quarters of the world by many animals. It is well known that pigs are employed
[24] Mr. J. Mansel Weale, `Nature,' April 27, 1871, p. 508.
[25] `Journal of Researches during the Voyage of the "Beagle," ' 1845, p. 96. I have compared the rattling thus produced with that of the Rattle-snake.
[26] See the account by Dr. Anderson, Proc. Zool. Soc. 1871, p. 196.
[27] The `American Naturalist,' Jan. 1872, p. 32. I regret that I cannot follow Prof. Shaler in believing that the rattle has been developed, by the aid of natural selection, for the sake of producing sounds which deceive and attract birds, so that they may serve as prey to the snake.
It seems at first a probable conclusion that venomous snakes, such as the foregoing, from being already so well defended by their poison-fangs, would never be attacked by any enemy; and consequently would have
{note [27] continued} I do not, however, wish to doubt that the sounds may occasionally subserve this end. But the conclusion at which I have arrived, viz. that the rattling serves as a warning to would-be devourers, appears to me much more probable, as it connects together various classes of facts. If this snake had acquired its rattle and the habit of rattling, for the sake of attracting prey, it does not seem probable that it would have invariably used its instrument when angered or disturbed. Prof. Shaler takes nearly the same view as I do of the manner of development of the rattle; and I have always held this opinion since observing the Trigonocephalus in South America.
[28] From the accounts lately collected, and given in the `Journal of the Linnean Society,' by Airs. Barber, on the habits of the snakes of South Africa; and from the accounts published by several writers, for instance by Lawson, of the rattle-snake in North America,--it does not seem improbable that the terrific appearance of snakes and the sounds produced by them, may likewise serve in procuring prey, by paralysing, or as it is sometimes called fascinating, the smaller animals. no need to excite additional terror. But this is far from being the case, for they are largely preyed on in all quarters of the world by many animals. It is well known that pigs are employed