44 UNIVERSAL EVOLUTION 



ferences of form, and structure otherwise, as fish, rep- 

 tiles, birds, and mammals, then all these differences must 

 be variations of, and derivations from, a common ances 

 tor, having only one form, and a backbone. 



The great variety of forms in the vertebrate division, 

 is a differentiation of structure that is called adaptive. 

 But the inner vertebral structure persists through all 

 the variations, and this classifies the orders of fish, rep- 

 tile, bird, and mammal, under the single division verte- 

 brate. The same principle applies to each of the other 

 divisions of the animal kingdom, viz. : ' ' Mollusca, Arti- 

 culata, Radiata and Protozoa. In each it is a persistent, 

 and unadaptive structure, often obscure, which mar- 

 shals the different orders, group by group, with their 

 great variations of outward form, under these five great 

 divisions. For example, man's vertebral and mammal- 

 ian structures do not dissociate him from the order of 

 vertebrate mammals, although his superior brain and its 

 psychial manifestations do. But the latter are such 

 variable qualities, that they cannot be used as bases of 

 classification. They are secondary characters, having 

 grown out of the physical. The physical and genealogi- 

 cal, alone, can be made the basis of classification. He, 

 therefore, must be classified as a family of the order of 

 mammals. He was, therefore, not created at the head 

 of the animal kingdom. 



Classification of plants and animals is made in groups 

 subordinate to groups. This can be done only because 

 of structural resemblances, and structural differences. 

 For example, a porpoise lives in the water and has the 

 form and habits of a fish. Yet it gives suck to its off- 

 spring, and is therefore a mammal. It is rare to find a 

 mammal an inhabitant of the water. The order as a 

 whole is terrestrial. Yet it is clear that the whale, the 



