49 COSMIC FHILOSOFHY. [pt. n. 



single item of positive evidence will always cutweigh any 

 amount of negative evidence. A single case in which two 

 or three species or genera are demonstrably connected with 

 each other through lineally intermediate forms, is enough 

 to outweigh the case of a thousand species or genera in 

 which no such linear connection has yet been demonstrated. 

 Now there can be no question that Equus, Ilipparion, and 

 Anchifhermm, are quite distinct genera; and a comparison 

 of the skeletons of the three leaves it equally unquestion- 

 able that the hipparion is simply a more ancient horse, and 

 that the anchitherium is simply a more ancient hipparion. As 

 Prof. Huxley observes, " the process by which Anchitherium 

 has been converted into Equus is one of specialization, or 

 of more and more complete deviation frpm what might be 

 called the average form of an ungulate mammal. In the 

 horses, the reduction of some parts of the limbs, together 

 with the special modification of these which are left, is 

 carried to a greater extent than in any other hoofed mam- 

 mals. The reduction is less and the specialization is less 

 in the hipparion, and still less in the anchitherium ; but 

 yet, as compared with other mammals, the reduction and 

 specialization of parts in the anchitherium remain great." ^ 

 But as we go back still farther into the Eocene epoch, we 

 find Plagiolophus, a genus intermediate between the horse 

 and the agouti, in which the reduction and specialization 

 of parts is still less. Here, where the exploration has 

 been relatively complete, the intermediate forms are so 

 numerous as to leave no doubt whatever as to the genetic 

 kinship.2 And similarly of the rhinocerotidse and hysenidae 



1 Critiques and Addressns, p. 195. 



• I may add that, in particular, numerous extinct forms intercalary between 

 man and ape are likely to be discovered when we search for them in those 

 parts of the earth where they are likely to exist, — namely, in Africa, ilada- 

 f^asear, South-eastern Asia, and the Malay Archipelago. Such forms are not 

 likelv, however, to be directly intermediate between man and the gorilla or 

 the chimpanzee. For these are probably aberrant types, and the connection 

 between man and the authropoid apes is to be sought much lower down,— 



