n 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 pursuits 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
as a moral principle," was well lived up to, yet ideal prepossessions
often had much to do with his marshalling of the facts.

Another professor at Munich, from whom Agassiz learned much, and had
nothing to unlearn, was the anatomist and physiologist Doellinger. 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 zooelogy 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 zooelogical companion of Martius in Brazilian
exploration, died in 1826; the fishes of the collection were left
untouched. Martius recognized the genius of Agassiz, and offered him,
and indeed pressed him, to undertake their elaboration. Agassiz brought
out the first part of the quarto volume on the "Fishes of the Brazilian
Expedition of Spix and Martius" before he took his degree of doctor of
philosophy, and completed it before he proceeded to that of doctor in
medicine, in 1830. The work opened his way to fame, but brought no
money. Still, as Martius defrayed all the expenses, the net result
compared quite favorably with that of later publications. Moreover, out
of it possibly issued his own voyage to Brazil in later years, under
auspices such as his early patron never dreamed of.

This early work also made him known to Cuvier; so that, when he went to
Paris, a year afterward,