The Snake's Warning.

Otago Witness, Issue 2895, 8 September 1909, Page 74

The Snake's Warning.

T« the human mind the rattle of the

rattlesnake and the expanded hood of t!h© cobra seem to add horror to tihe character of these venomous reptiles; but this is due to a mistaken association of ideas, because in reality we should regard these peculiarities with gratitude, since they have doubtless been the means of saving countless human lives. Hearing the warning rattle on the ground or viewing the "hooded death" waving to amd fro at a little height above it, the human, being has a golden opportunity to withdraw in time from the zone of danger. We need not, however, flatter ourselves that the ca v ing of human Jife was the reason why these deadly snakes are- thus curiously equipped. The advantage to the reptiles themselves was the col© factor in the case; and so far as human beings are concerned, it is very rarely indeed that we find any evidence of .human influence in the development of wild creatures. Man, as an intelligent creature, is too recent to haveleft much imprint upon the tablets of evolution at large. Indeed, as a rule, man seta at naught all the rules of Nature, and turns the safeguards of wild life to its undoing. In the case of the rattlesnake and the cobra, for instance, the human being does not, as a grazing animal would, merely turn aside and leave the meonacnMr reptile afone. Instead, on recovering from the shock of the sudden peril, his first thought is to slay the creature which warned him. Thus, so ' far as the -relations between man and snakes are concerned, it would 1 be far 'better for the ratfler not to rattle* and for the cobra to 6trike first and expand its hood, if it chose, afterwards. However, as I have said, the rattle and the hood were not acquired for the purpose oi warning intelligent human beings; and so far as other animals are concerned, no doubt they are most useful means of saving the snakes from being accidentally trampled upon. Thus viewed, one is almost tempted to describe them as " ingenious devices," especially the appond&go of the rattlesnake Thi6 consists of a number of bony plates, which rattle aga'nst one another when the alarmed snake vibrates its tail. Originally, no doubt, the evolutionist will say, the snake merely used the habit of warning approaching animals by vibrating its tail, thue causing the herbage to shake and rustle. The next; step would be a hardening of tihe tailend to do this more effectually ; and by degrees the highest combination of hardness and flexibility would be reached in the desiccated tail becoming a series oi flat, bony joints. Similarly the power which the cobra possesses of cxpand'ng the skin on each side of its neck would dp explained as the resuit of a. lonj series of minute changes, eacn tending to make tK> uplifted head and neck of the reptile more- conspicuous and alarming. When thj cob^a is not excited there, is scarcely any tracs of the hood visible It looks just like any other snake. But •when the nood ia-fuiiy spread and waves to and fro, threatening to strike, the creature' 3 formidable character seems quadrupled, especially when one can see the weird Vshaped mark with v.hich it is then usually adorned. The ordinary markings of snakes also no doubt have a deterrent effect upon animals which see them at close .quarters; for grazing animals are v^ry timid and start back from any object who=e shape and colouring they do not understand. At the same thno no doubfc the primary effect of the markings 13 protect ivo. Even the splendid patterns . upon the great pythons have this effect, causing th-a creatures, when they ar? coiled up, to look like lumps of variegated rock. This is because tho markings break up the outline of the snake ; and we can see in birds' eggs which i.T© laid' upon the ground that tli-3 blotches and markings have the same effect. It may plainly be seen also in the markings of moths which sit upon troe trunks, or beetles which hide upon lichen, and so on.— W. S. Bekbidge.