JAMES DWIGHT DANA 249 



by Darwin and Wallace. Agassiz remained till his death a strenu- 

 ous and bitter antagonist of the evolution theory. Dana at first 

 opposed the theory, but later, with characteristic candor, gave it 

 a somewhat qualified assent. 



About the middle of the nineteenth century, the majority of natu- 

 ralists regarded the theory of evolution in any form as dead beyond 

 hope of resurrection. The general conception of transmutation 

 of species was supposed to have been buried in the same grave 

 with the crudities of Lamarck and of the "Vestiges of Creation." 

 Weismann says, "We who were then the younger men, studying 

 in the fifties, had no idea that a theory of evolution had ever been 

 put forward, for no one spoke of it to us, and it was never men- 

 tioned in a lecture." Dana himself, in his Thoughts on Species* 

 had formulated the somewhat metaphysical doctrine that "a 

 species corresponds to a specific amount or condition of concen- 

 tered force defined in the act or law of creation." This formula 

 was supposed to apply alike to chemical elements and compounds 

 the species of the inorganic world and to the species of plants 

 and animals. The permanence of species seemed to follow a 

 priori from this conception. Dana was also disinclined to the 

 theory of evolution on theological grounds, since he was under the 

 influence of a phase of natural theology then prevalent, which 

 found the most convincing evidence of a personal God in the sup- 

 posed breaks in the continuity of nature. Another cause of the 

 lateness of Dana's accession to the evolution theory was the fact 

 that the date of publication of the Origin of Species, approxi- 

 mately coincided with the date of the breakdown of Dana's health. 

 On this account he did not read Darwin's book for several years 

 after its publication, and naturally failed to appreciate how greatly 

 the status of the evolution theory was changed. We know from 

 the correspondence between Dana and Darwin that Dana did not 

 read the Origin till some time after February, 1863. 



In the second edition of the Manual of Geology (1871), Dana 

 still maintained the permanence of species. "Geology," he de- 

 clared, "has brought to light no facts sustaining a theory that 

 1 American Journal of Science, series 2, vol. 24, pp. 305-316. 



