PARALLELISM. 205 



tebrata. I have pointed out 1 that in the structure of 

 his extremities and dentition, he agrees with the type 

 of Mammalia prevalent during the Eocene period 

 (cfr. Phenacodus). Hence in these respects he re- 

 sembles the immature stages of those mammals which 

 have undergone special modifications of limbs and ex- 

 tremities, such as Ungulata in which caenogeny has 

 not obliterated the early stages from the embryonic 

 record. These forms are probably extinct. I have 

 also shown 2 that in the shape of his head man resem- 

 bles the embryos of all Vertebrata, in the protuberant 

 forehead, and vertical face and jaws. In this part of 

 the structure most Vertebrata have grown farther from 

 the embryonic type than has man, so that the human 

 face may be truly said to be the result of a process of 

 retardation. Nevertheless, in the structure of his ner- 

 vous, circulatory, and for the most part, of his repro- 

 ductive system, man stands at the summit of the Ver- 

 tebrata. It is in those parts of his structure that are 

 necessary to supremacy by force of body only, that 

 man is retarded and embryonic. 



5. OBJECTIONS TO THE DOCTRINE OF PARAL- 

 LELISM. 



An objection to the theory of parallelism in its full 

 sense has been recently put forward by Mr. C. Her- 

 bert Hurst. 3 He says, "My object now is to show 

 that in neither case can a record of the variation at 

 any one stage of evolution be preserved in the ontog- 

 eny, much less can the ontogeny come to be a series of 



1 " The Relation of Man to the Tertiary Mammalia," Penn Monthly, 1875; 

 Origin of the Fittest, 268. 



2 " The Developmental Significance of Human Physiognomy," American 

 Naturalist, June, 1883 ; Origin of the Fittest, 1887, p. 281. 



ZXatural Science, 1893, p. 195. 



