156 BULLETIN OF DENISON UNIVERSITY. 
penhagen assumed Chamisso’s facts as correct, but in an extended 
treatise, in 1841, thus after Chamisso’s death, proposed another ex- 
planation. * * * Almost immediately after this, in 1842, Chamisso’s 
view found in the same place a defender, and his fame a herald, in 
our corresponding member Herr Japetus Steenstrup. He succeeded 
in distinguishing upon the wide field of the doctrine of propagation, — 
a field abounding in strange things, — a series of development processes, 
which as a whole can be explained from the point of view of alternation 
of generations, which Chamisso had first recognized and named. * * * 
Processes of development in the medusae, strobilae, cercariae and dis- 
toma, and aphidae or plant-lice, and later others besides, were thus at 
one stroke made plain. Johannes Muller’s famous discoveries con- 
cerning the development of echinoderms formed a step of transition 
between the phenomena of alternation of generations and those of 
metamorphosis, of which *the frog and butterfly afford the best known 
instances. The merit of having opened this way belongs, as Herr 
Steenstrup expressly declares, to Chamisso.” 
Though sharing in the erroneous view at the time prevalent con- 
cerning the coral insect (that it builds its wonderful structure up from 
immeasurable depths), yet he contributed to the understanding of the 
subject by observing that the coral grows most rapidly in a violently 
agitated sea. This more rapid growth, however, he did not ascribe to 
the real cause, (that the surf secures the insect its needed nourishment), 
but merely to the mechanical action of the waves'. Not for the cor- 
rect theory of their formation, but for his careful study of their present 
condition as the abodes of men, does he deserve credit in connection 
with the coral islands. 
In concluding his discussion of Chamisso’s contributions to zool- 
ogy Du Bois-Reymond says : ‘^We should be in error, if we imagined 
Chamisso’s zoological observations directed, according to the manner 
latterly preferred, only upon the lower animal forms, such as salpae 
and coral insects. With just as close attention the vertebrate animals 
ot all latitudes were observed : the flying fish, the birds that perched 
