G. GENERAL NATURAL HISTORY AND ZOOLOGY. 279 



the cephalic extremity ; and, secondly, because form in nat- 

 ure's species is, with some limitations, an expression of 

 force." 



" We recognize, as evidence of upward progress in man, an 

 increasinor heisfht, width and erectness of the forehead, and a 

 shortening of his jaws, and see therein evidence of improved 

 intellect; which means higher grade of cephalization. But, 

 more than this, the erect form of man, the shortened arms, 

 the naked skin, as well as the large, smooth-surfaced cranium, 

 may also be as directly and necessarily connected with and 

 dependent upon his superior degree of cephalization in the 

 system of animal life ; while the hairy skin, the long arms, 

 the crested skull, the inclined posture of the man-ape, may be 

 all involved in the ape's inferior degree of cephalization. If 

 so, the development of the brain in man, and of all the high- 

 est structural perfections of the vertebrate type which he ex- 

 hibits, is inconsistent with the existence of the hairy covering 

 and some other circumferential as well as interior character- 

 istics of the brute." In tliis article Professor Dana seems to 

 indorse in a partial way the doctrine of evolution, remarking 

 that "the present state of science favors the view of progress 

 through the derivation of species from species, with few oc- 

 casions for divine intervention. If then there has been der- 

 ivation of species from species, we may believe that all 

 actual struggles and rivalries among animals, leading to a 

 'survival of the fittest,' must tend, as in man, to progress in 

 cephalization, and dependent structural changes. In fact, 

 mere living, the surmounting of the daily obstacles in getting 

 food and shelter and satisfying ordinary desires, may have 

 given growth to the brains and structures of the Eocene 

 mammals, aiding, but perhaps exceeding, all other influences 

 from environments. The source of variation here pointed 

 out is not at all at variance with Darwinism. Darwin, in 

 fact, does not aim to explain the origin of variation among 

 species, but chiefly the workings of natural selection vari- 

 ations being in progress by some means in leading to the 

 'survival of the fittest' of the varieties. Variation he refers 

 to environments, and especially to action on the genital sys- 

 tem. The genital system may have this prominence in 

 plants, but for animals I would give the nervous system the 

 higher place, inasmuch as upon it environments make their 



