HISTORICAL GEOLOGY 113 



of evolution in America, more can be had from Dana's 

 paper on Asa Gray (35, 181, 1888). Here we read, as a 

 sequel to his Thoughts on Species, that the "paper may 

 be taken, perhaps, as a culmination of the past, just as 

 the new future was to make its appearance." Finally, 

 in this connection there should be mentioned 0. C. 

 Marsh's paper on Thomas Henry Huxley (50, 177, 1895), 

 wherein is recorded the latter 's share in the upbuilding 

 of the evolutionary theory. 



We have seen that originally Dana was a creationist, 

 but in the course of his long and fruitful life he gradually 

 became an evolutionist, and rather a Neo-Lamarckian 

 than a Darwinian. This change may be traced in the 

 various editions of his Manual of Geology, and in the last 

 edition of 1895 he says his "speculative conclusions" of 

 1852 in regard to the origin of species are not "in accord 

 with the author's present judgment." "The evidence in 

 favor of evolution by variation is now regarded as essen- 

 tially complete." On the other hand, while man is 

 "unquestionably" closely related in structure to the 

 man-apes, yet he is not linked to them but stands apart, 

 through "the intervention of a Power above Nature. 

 . . . Believing that Nature exists through the will and 

 ever-acting power of the Divine Being, and . . . that the 

 whole Universe is not merely dependent on, but actually 

 is, the Will of one Supreme Intelligence, Nature, with 

 Man as its culminant species, is no longer a mystery." 



In America most of the paleontologists are Neo- 

 Lamarckian, a school that was developed independently 

 by E. D. Cope (1840-1897) through the vertebrate evi- 

 dence, and by Alpheus Hyatt (1838-1902) mainly on the 

 evidence of the ammonites. They hold that variations 

 and acquired characters arise through the effects of the 

 environment, the mechanics of the organism resulting 

 from the use and disuse of organs, etc. One of the lead- 

 ing exponents of this school is A. S. Packard, whose book 

 on Lamarck, His Life and Work, 1901, fully explains the 

 doctrines of the Neo-Lamarckians. 



The Growth of Invertebrate Paleontology. 



How and by whom paleontology has been developed 

 has been fully stated in the Journal in a very clear man- 



