232 The American Naturalist. (March, 
All doubt is thus removed, and it may be regarded as con- 
clusive that by bastard fertilization of whole eggs or protoplas- 
mic pieces having nuclei, larve are formed that stand midway 
between the larval forms of the parent species; but the larvae 
arising from the enucleated fragments of eggs have entirely 
the characteristics of the parent (male) species. Herewith is 
demonstrated the law that the nucleus alone is the bearer of 
hereditary qualities. With the removal of the maternal nucleus 
are removed at the same time the maternal hereditary ten- 
dencies of the egg. And the maternal protoplasm, although 
in this case furnishing a large share of the material for the 
development of the new organism, is without influence on the 
form of the organism. 
The phenomenon of growth of the enucleated protoplasmic 
mass is entirely governed by the introduced spermatozoon, and 
indeed to conclude by analogy, by the nucleus of the sperm. 
Whether the spermatic nucleus penetrates the egg protoplasm 
of its own species or of another species, the same result appears, 
namely, the larva is that of the male species. I might say 
that the nucleus possesses an assimilating power toward the 
protoplasm, since it produces the same sort of organism from 
material that appears to be different, according to our stand- 
ards of truth. That the egg-protoplasm is similar in the two 
cases in every respect pertaining to its chemical constitution, 
I cannot admit, and do not even hold to be probable. Still 
such differences may, if they were present, be very easily 
explained, as due to the previous action of that nucleus, to 
which the enucleated protoplasm was at one time united, and 
any difference would thus not be incompatible with the law 
that all changes of form of the protoplasm are dependent on the 
constitution of the nucleus. 
