22 
New Researches on the 
[January, 
the ovum, and the changes which the spermatozoon expe- 
riences in this period. He takes up next the formation of 
the male and the female pronucleus, the fecundation and 
the segmentation of the first embryonal cell. Finally he 
gives the conclusions deduced from the results of his ob- 
servations, which we shall here summarise from the “Archives 
de Biologie ” and the “ Naturforscher ” : — 
The ovarian ovum yields to the ovum-gonocyte a proto- 
plasmic body (which is reduced by the absence of the matter 
forming the strata deposited around the yolk), and a nucleus 
which is reduced by the repulsion of the partly chromatic 
and partly achromatic elements which enter into the 
composition of the polar vesicles. The germinal vesicle 
undergoes a first reduction at the time of its apparent dis- 
appearance. A part of its substance is then mixed with the 
protoplasm of the egg, and this reduced nucleus is the 
female pronucleus. 
On a former occasion I used the term gonocyt to express 
a cell-body which possesses two nuclear elements with 
different sexual properties. I have applied this name to the 
organism of the Infusoria which possess an endoplasm and 
an endoplastula, and also to the body of the ovum which 
possesses both pronuclei. But it follows clearly, from the 
study of fecundation in Ascaris megalocephala, that an ovum 
possessing its two pronuclei is exactly the equivalent of an 
ordinary cell. I have proved that in the nuclei of each of 
the two first blastomeres (segmentation-cells) we find the 
equivalent of a male semi-pronucleus and a female semi- 
pronucleus. It is also probable that the same will hold good 
in the cells thence derived. A cell with a single nucleus 
differs thus in nothing from a cell with two distinct pro- 
nuclei. 
An examination of the division of a cell with two pro- 
nuclei shows that it takes place exactly like that of a single 
cell. A cell with two pronuclei cannot, therefore, require a 
distinctive name. It is useless therefore to employ the word 
gonocyt in order to denote this hermaphroditic element, or 
any other cell. But instead of banishing this word from 
the vocabulary of the cell-doctrine (we hesitate at saying 
cellology) it seems to me that it might be usefully retained 
in a modified acceptation. I propose to use it with the 
respective addition of the adjectives “ female ” or “ male,’’ 
in order to designate the ovum reduced in consequence of 
its ripeness, and the spermacyt after the repulsion of its cyto- 
phoral portion after it has become a spermatozoid. 
But if from a morphological point of view, and considered 
