And despite the attention of naturalists for above two hundred years, it is not yet done with. First its rattle, then its fangs, next its maternal affection and the security offered to its young in ‘its own bosom,’ then its ‘pit,’ and again its rattle—each and all in turn have continued to occupy the pen of zoologists as, with the advance of science, fresh light has been thrown upon ophiology. American naturalists have continually something new to tell us about the _Crotalus_, and not even yet have they decided among themselves of what precise use that remarkable rattle is, either to its owner or its auditors. The various theories regarding its construction, mode of growth, its age and supposed uses, will occupy the second part of the present subject; other rattlesnake features will come in their places, but first an outline of what the early English writers had to say about it will not be devoid of interest. Natural history as a science was then in its infancy. The Royal Society of England had as yet no existence; snakes were ‘insects,’ because they lay eggs; insects were ‘serpents,’ because they creep; and the majority of all such ‘creeping things’ were ‘venomous,’ of course. In those early days of science there was little or no recognition of species, two, or at most three, different kinds of rattlesnakes being named. The distinguishing rattle seemed enough to separate them from all other snakes: they were ‘the vipers with the bell,’ or ‘the vipers with the sounding tail.’ ‘Vipers’ they were at once decided to be, conformably with the old idea that vipers, in distinction to every other kind of snake, produced their young alive. In this respect those early observers were correct; and from their general characteristics they are still _vipers_ in the eyes of science: that is, they belong to the sub-order _Viperina_, though their dentition more than any other feature separates them from the rest, and we know now that several non-venomous snakes produce live young as well as the vipers. In appearance the rattlesnake is so well known that a minute description of it is uncalled for. Throughout the whole genera of the _Crotalidæ_ the viperine character is seen in the broad, angular, flattish head; the thinner neck, distinct between it and the thicker body; a short, tapering tail, and a generally repulsive appearance with an evil expression about it, as if no further warning were required to announce its deadly qualities. Nevertheless, many of the rattlesnakes possess an undeniably handsome exterior. Their colours are for the most part dark and rich, relieved with lighter markings and velvety black; often wearing a brilliant prismatic hue, which still further enriches their tints. And then the rattle at once announces the name of its owner.