In the above illustrations it will be seen that not only do rattles differ in form in various species of snakes, but that the links themselves differ in form in one and the same rattle. Some of them are broader than others, some wider, and some more compressed. In all the above drawings I carefully and faithfully copied the originals. And in this variability we can only refer again to claws, nails, horns, feathers, etc., which are seen to differ in the same individual, according to health, season, or accident. Where great numbers of rattlesnakes have been killed in one locality, as, for instance, during the ‘spring campaigns,’ their tails have presented on an average from fifteen to twenty links each. Holbrooke[83] has seen one of twenty-one links. A Crotalus at the London Reptilium had twenty-five links at one time; then ten of them got broken off, but still a respectably-sized rattle remained. The longer the rattle, the greater the risk of injury. Oliver Wendell Holmes, in his wonderful story _Elsie Venner_, states that a snake in the locality where the Rocklands ‘Rattlesnake Den’ existed, had forty joints in its rattle, and was supposed, after Indian traditions, to have killed forty people. He tells us that the inhabitants of those parts were remarkable for acute hearing even in old age, from the practice of keeping their ears open for the sound of the rattle whenever they were walking through grass or in the woods. And whenever they heard the rattling of a dry bean-pod, they would exclaim, ‘Lord, have mercy upon us!’ the sound so strongly resembling that of the dreaded Crotalus. Another American naturalist records a snake with forty-four links to its rattle, but adds that this occurrence is rare and ‘a great curiosity.’ So one would imagine, and that the fortunate possessor of such an ensign must have flourished in smooth places. More favoured still was a snake mentioned in the vol. of the _Philosophical Transactions_ just now quoted, and in which Paul Dudley had ‘heard it attested by a Man of Credit that he had killed a Rattlesnake that had between 70 and 80 Rattles (_i.e._ links), and with a sprinkling of grey Hairs, like Bristles, all over its Body.’ As this venerable Crotalus must have rusticated nearly two hundred years ago, we must accept the tale or tail with caution. The family of the _Crotalidæ_, it will be borne in mind, embraces a large number of serpents with only a rudimentary rattle; a number with only the horny spine (see p. 176); and a few with a rattle so small even when fully developed, that they are received into the family by courtesy rather than by their ‘sounding tail.’ [Illustration] A small snake with this pretence of a rattle is dangerous because it is so indistinctly heard. This is also the case with _Crotalus miliarius_, whose rattle is so feeble as to be scarcely audible a few feet off. So much for the size of rattles. Now for the development of them.