184 THE AMERICAN NATURALIST: [VOL XXXII. 
pointed out the way. Again, if it be said that Agassiz created 
numerous species on too slender grounds of distinction, does 
not this merely express the refinement of his personal equation 
in the art of discerning differences between allied forms of 
organisms, for which compensation is easily possible ? 
Aside from the classic works just noticed, Agassiz contributed 
very little to the subject of paleichthyology. A few minor 
papers appeared in different journals, or were appended to 
geological monographs by other authors (Murchison, de Verneuil, 
Keyserling, etc.), prior to his departure for America. In this 
country his attention was so diverted in other directions that 
he was unable to prosecute further original investigation. Some 
informal reports on fossil fishes were prepared by him at the 
meetings of the American Association for the Advancement of 
Science (at one of which, the Cincinnati meeting, in 1851, he 
offered some surprising comments on Macropetalichthys), and 
brief notes on the fishes of the Virginia Coalfield were contrib- 
uted to Lyell’s account of the geology of the basin in 1847. 
With these exceptions, the only paper from his pen on fossil 
fishes in America is that appended to the fifth volume of the 
Pacific Railroad Surveys,! published in 1856. It is also rather 
remarkable that he succeeded in interesting only one student 
of his to take up this line of research seriously; this was Mr. 
Orestes St. John, well known from his writings on Carboniferous 
fishes from Illinois and other western states. 
Many have wondered why Agassiz, with all his wealth of 
information, his fertility of imagination, and after having dis- 
covered the very laws which constitute so important a bulwark 
in the theory of evolution, should persistently have opposed that 
doctrine, although his work on fossil fishes prepared the way 
for it most admirably. There can be no doubt that his mind 
was closed to such conclusions through the influence of precon- 
ceived ideas, on which it is unnecessary for us to dwell. His 
position with reference to the evolutionary hypothesis has been 
1 Explorations and Surveys for a Railroad Route from the Mississippi River to 
the Pacific Ocean. Report of Explorations in California, by Lieut. R. S. William- 
son, vol. v, Washington, 1856. (Abstract of Agassiz’s article in Amer. Journ. Sci. 
[2], vol. xxi, 1856, p. 274.) 
