II THE CLASSIFICATION OF MAN 93 



a marvellous likeness of organization. He re- 

 sembles them as they resemble one another he 

 differs from them as they differ from one another. 

 And, though these differences and resemblances 

 cannot be weighed and measured, their value may 

 be readily estimated ; the scale or standard of 

 judgment, touching that value being afforded and 

 expressed by the system of classification of animals 

 now current among zoologists. 



A careful study of the resemblances and differ- 

 ences presented by animals has, in fact, led 

 naturalists to arrange them into groups, or 

 assemblages, all the members of each group 

 presenting a certain amount of definable resem- 

 blance, and the number of points of similarity 

 being smaller as the group is larger and vice versa. 

 Thus, all creatures which agree only in presenting 

 the few distinctive marks of animality form the 

 Kingdom ANIMALIA. The numerous animals 

 which agree only in possessing the special 

 characters of Vertebrates form one Sub-kingdom 

 of this Kingdom. Then the Sub-kingdom 

 VERTEBRATA is subdivided into the five Classes, 

 Fishes, Amphibians, Reptiles, Birds, and Mammals, 

 and these into smaller groups called Orders; 

 these into Families and Genera ; while the 

 last are finally broken up into the smallest 

 assemblages, which are distinguished by the 

 possession of constant, not-sexual, characters. 

 These ultimate groups are Species. 



