Many of my observant readers have already discovered for themselves where and what these numerous legs and feet are. In the early days of my ophidian studies, which then consisted chiefly of observations, I noticed the action of limbs beneath the skin of the pythons as they moved about, and more particularly when they were climbing up the glass in front of their cages, and as in the case of the glottis, I thought I had made a grand discovery; and so I had, as far as myself was concerned.
Deductions from personal observation, which in the history of many sciences have again and again been claimed as original discoveries by rival thinkers or experimentalists, no doubt were original on the part of each.
Probably, also, many other persons have noticed this leg-like action of the ribs, but who, not being specially interested in snakeology, have never troubled themselves to ascertain ‘further particulars,’ or cared whether any one else had observed this or not. But it is a very evident and unmistakeable action, and one quite worth studying on your next visit to the Reptilium.
Books on ophiology tell us that Sir Joseph Banks was the first to observe this limb-like action of the ribs. Sir Everard—then Mr.—Home, F.R.S, and the most distinguished anatomist of his time, was, however, the first to publish a scientific description of the fact; his account and the illustrations accompanying it having been subsequently adopted by most ophiologists.
In vol. cii. of the Philosophical Transactions of 1812, p. 163, is a paper which was read before the Royal Society in February of that year, by Everard Home, Esq., F.R.S. It is entitled, ‘Observations to show that the Progressive Motion of Snakes is partly performed by the Ribs.’
We give his introductory words, not only because the ‘discovery’ was a great event in the history of ophiology, but as showing that to see and examine a foreign snake was at that time a rare if not a novel occurrence. He tells us that on a former occasion in 1804, he had described the anterior ribs of a cobra, those which form the ‘hood.’ At that time he was ‘not in possession of the bodies of snakes,’ so that he could compare their structure, but had since found out a good deal more about their anatomy, and then he proceeds: ‘A Coluber of unusual size lately brought to London to be exhibited, was shown to Sir Joseph Banks. The animal was lively and moved along the carpet briskly; while it was doing so, Sir Joseph thought he saw the ribs come forward in succession, like the feet of a caterpillar. This remark he immediately communicated to me, and gave me an opportunity of seeing the snake and making my own observations. The fact was already established, and I could feel the ribs with my fingers as they were brought forward. I placed my hand under the snake, and the ribs were felt distinctly upon the palm as the animal passed over it. This becomes the more interesting discovery as it constitutes a new species of progressive motion, and one widely different from those already known.’
The ‘unusually large Coluber’ was probably a python. Had a previous opportunity presented itself to this scientific and thoughtful observer, Sir Joseph Banks might not have been the one to carry off the palm in this discovery. Home had already described the peculiarity of the cobra’s anterior ribs (chap. xviii.), and, as already suggested, it is scarcely possible to watch one of those larger constrictors without perceiving the mode of progression. We shall see in the course of this book that snake observers have arrived at the same conclusions on several points, while wholly ignorant of what others had said or decided regarding the same.
In the previous chapter the number of vertebræ forming the spinal column of three or four snakes was given, but this number varies greatly, not only in snakes but in species. In some species there are above 400 vertebræ or joints in a snake’s spine. But here is a puzzle that baffles the student. ‘Every one knows,’ says Schlegel, ‘that their number differs’ (speaking of the vertebræ), ‘not only according to the species, but also in individuals, so that sometimes we find in serpents of the same species a difference of thirty or forty vertebræ more or less.’[68]
Taking this literally according to the text, one might expect to find one ring-snake in a family of ten measuring two feet, while his brother measured two yards, and a third four feet, and so on, as if each had a different number of vertebræ.
‘The same species,’ that is, two anacondas or two cobras! ‘A mistranslation,’ one naturally decided, and proceeded to consult the original. But no. The translator had faithfully and unquestioningly followed the original French; but the fact was so irreconcilable that I sought Dr. Günther’s kind assistance in comprehending the passage.