64 THE PHYSICAL KINSHIP 



we find the great sub-class of the placentals, which 

 to-day comprises more than two thousand five 

 hundred species, represented by only a small 

 number of insignificant pro-placentals, in which 

 the characters of the four divergent orders are so 

 intermingled and toned down that we cannot in 

 reason do other than consider them as the pre- 

 cursors of those features. The oldest primates, 

 the oldest ungulates, the oldest carnivora, and the 

 oldest rodents, all have the same skeletal structure 

 and the same typical dentition (forty-four teeth) 

 as these pro-placentals; all are characterised by 

 the small and imperfect structure of the brain, 

 especially of the cortex, its chief part, and all 

 have short legs and five-toed, flat-soled (planti- 

 grade) feet. In many cases among these oldest 

 placentals it was at first very difiicult to say 

 whether they should be classed with the primates, 

 ungulates, carnivora, or rodents, so very closely 

 and confusedly do these four groups, which diverge 

 so widely afterwards, approach each other at that 

 time. Their common origin from a single ances- 

 tral group follows incontestably ' (5). 



g. Man is the most powerful and influential of 

 animals. He rules the world — rules it with a 

 sovereignty more despotic and extensive than that 

 hitherto exercised by any other animal. Many 

 races of beings are, and have been for centuries, 

 completely dominated by him. These races, 

 during their long subjection, have been changed 

 and transformed by man in a wonderful manner 

 through his control of their power to breed. All 



