LOUIS AGASSIZ. 485 
away by it, — probably because they were such keen and con- 
scientious observers, and were kept in close communion with 
work-a-day Nature. As Agassiz intimates, they had to resist 
“the temptation to impose one’s own ideas upon Nature, to 
explain her mysteries by brilliant theories rather than by 
patient study of the facts as we find them,” and that “ over- 
bearing confidence in the abstract conceptions of the human 
mind as applied to the study of nature ;” although, indeed, he 
adds, “‘the young naturalist of that day who did not share, in 
some degree, the intellectual stimulus given to scientific pur- 
suits by physio-philosophy would have missed a part of his 
training.” That training was not lost upon Agassiz. Although 
the adage in his last published article, ‘“‘ A physical fact is as 
sacred asa moral principle,” was well lived up to, yet ideal 
prepossessions often had much to do with his marshaling of 
the facts. 
Another professor at Munich, from whom Agassiz learned 
much, and had nothing to unlearn, was the anatomist and 
physiologist Dollinger. He published little; but he seems to 
have been the founder of modern embryological investigation, 
and to have initiated his two famous pupils, first Von Baer, 
and then Agassiz, into at least the rudiments of the doctrine 
of the correspondence between the stages of the development 
of the individual animal with that of its rank in the scale of 
being, and the succession in geological time of the forms and 
types to which the species belongs: a principle very fertile 
for scientific zodlogy in the hands of both these naturalists, 
and one of the foundations of that theory of evolution which 
the former, we believe, partially accepted, and the other wholly 
rejected. 
The botanical professor, the genial Von Martius, should 
also be mentioned here. He found Agassiz a student, barely 
of age; he directly made him an author, and an authority in 
the subject of his predilection. Dr. Spix, the zodlogical com- : 
panion of Martius in Brazilian exploration, died in 1826; the 
fishes of the collection were left untouched. Martius recog- 
nized the genius of Agassiz, and offered him, and indeed 
pressed him to undertake their elaboration. Agassiz brought 
