CHAPTER XVII ON THE THEORY OF TRANSFORMATIONS, OR THE COMPARISON OF RELATED FORMS

Rodentia, especially the family of the Leporidae, and the more primitive Ungulates. For my part, I would go further; for I think there is strong reason to believe that the Perissodactyles are more closely related to the Leporidae than the former are to the other Ungulates, or than the Leporidae are to the rest of the Rodentia. Be that as it may, it is obvious from Fig. 400 that the rabbit〙s skull conforms to a system of {765} co-ordinates corôÙreôÙsponôÙding to the Cartesian co-ordinates in which we have inscribed the skull of Hyrachyus, with the difference, firstly, that the horizontal ordinates of the latter are transformed into equidistant curved lines, apôÙproxôÙiôÙmateôÙly arcs of circles, with their concavity directed downwards; and secondly, that the vertical ordinates are transformed into a pencil of rays apôÙproxôÙiôÙmateôÙly orthogonal to the circular arcs. In short, the configuration of the rabbit〙s skull is derived from that of our primitive rhinoceros by the unexpectedly simple process of submitting the latter to