CHAP. XX. NOT INCONSISTENT WITH FACTS. 397 



average proportion to the spinal cord of not more than two 

 to one, comes first, — it is the brain of the fish; that which 

 bears to the spinal cord an average proportion of two-and-a- 

 half to one succeeded it, — it is the brain of the reptile; then 

 came the brain avex'aging as three to one, — it is that of the 

 bird. Next in succession came the brain that averages as 

 four to one, — it is that of the animal ; and last of all there 

 appeared a brain that averages as twenty-three to one, — 

 reasoning, calculating Man had come upon the scene."* 



M. Agassiz, in his Essay on Classification, has devoted a 

 chapter to the ''Parallelism between the Geological Succession 

 of Animals and Plants and their present relative Standing;" 

 in which he has expressed a decided opinion that, within the 

 limits of the ordei-s of each great chiss, there is a coincidence 

 between their relative rank in organization and the order of 

 succession of their representatives in time.f 



Professor Owen, in his Palaeontology, has advanced similar 

 views, and has remarked, in regard to the vertebrata, that 

 there is much positive as well as negative evidence in support 

 of the doctrine of an advance in the scale of being, from 

 ancient to more modern geological periods. We observe, for 

 example, in the triassic, oolitic, and cretaceous strata, not 

 only an absence of placental mammalia, but the presence of 

 innumerable reptiles, some of large size, terrestrial and aqua- 

 tic, herbivorous and predaceous, fitted to perform the func- 

 tions now discharged by the mammalia. 



The late Professor Bronn, of Heidelberg, after passing in 

 review more than 24,000 fossil animals and plants, which he 

 had classified and referred each to their geological position 

 in his "Index Pala^ontologicus," came to the conclusion that, 

 in the course of time, there had been introduced into the 



•■■ Footprints of the Creator, p. 283. of United States, Part I. — Essay on 

 Edinburgii, 1849. Classification, p. 108. 



f Contributions to Natural History 



