Section 52. Take a Wider Range of Time and Vaster Changes of

condition than this, and it becomes possible to imagine how the social cattle-- with their united front against an enemy, fierce onslaught, and their general adaptation to prairie life-- have differentiated from the ancestors of the slight and timid deer; how the patient camel, with his storage hump, water storage, and feet padded against hot sand, has been moulded by the necessity of desert life from the same ancestral form. And so we may work back, and link these forms, and other purely vegetarian feeders, with remoter cousins, the ancestral hogs. Working in this way, we presently get a glimpse of a possible yet remoter connection of all these hoofed and mainly vegetarian animals, with certain "central types" that carry us across to the omnivorous, and, in some cases, almost entirely vegetarian bears, and to the great and prosperous family of clawed, meat-eaters. And thus we elucidate, at last, a thread of blood relationship between the, at present, strongly contrasted and antagonistic deer and tiger, and passing thence into still wider generalizations, it would be possible to connect the rabbit playing in the sunshine, with the frog in the ditch, the dog-fish in the sea-waters and the lancelet in the sand. For the transition from dog-fish to rabbit differs from the transition from one species of deer to another only in magnitude: it is an affair of vast epochs instead merely of thousands of years.