90 W M. Smallwood 
presence of deutoplasmie bodies in the eytoplasm. The growth is 
gradual and the material taken up is apparently in a liquid state 
as it enters the ovocyte. The deutoplasm inereases in amount until 
it completely fills the region between the nuclear wall and the cell 
membrane, thus concealing the structure of the cytoplasm. Before 
the egg is laid, the germinative vesicle is central in position. 
The changes in the nucleus may be readily observed. The 
nucleolus in a young ovocyte is a solid mass which takes a deep 
stain even before the nucleoli in the cells of the other parts of the 
body show much reaction to the same stain. A number of prominent 
linin fibres bear chromatic material. As the deutoplasm appears in 
the eytoplasm, small clear regions may be distinguished in the 
nucleolus, if the stain is not too intense. This is the beginning of 
the vacuolization of the nucleolus, the further metamorphosis of which 
is similar in effect to the changes in Piscicola repax and Tetrastemma 
elegans (MONTGOMERY, 99), and Zlaminea solitaria (SMALLWOOD, 04); 
but the process is different in so far as it eoncerns the method by 
which the chromatin is displaced. After the vacuoles begin to appear, 
the solid mass of chromatin breaks up into many small bodies (Fig. 1). 
This fragmentation of the nucleolus is aceompanied by a decrease 
in the amount of ehromatin until it disappears entirely. "The loss of 
chromatie material from the nucieolus prevents its fate from being 
followed during the early stages of maturation; when the chromo- 
somes are forming from the germinative vesicles, no trace of it is 
evident. 
Maturation. The earliest indication of the first maturation 
figure was found in a spawn-mass of M. Gouldiü that was fixed 
together with the animal as the spawn was being deposited. The 
eggs for a few minutes after they have been laid are irregular in 
shape, none in M. Gouldü being spherical. The eggs appear as if 
they had been forced through an opening too small for them and 
as a result had become elongated and kidneyshaped. Dentalium 
exibits a similar irregularity in shape but apparently not as marked 
(Wirson, 04). While in this irregular form, the germinative vesicle 
is found in any region of the ovum. Maturation begins at this time 
in this species. In Fig. 2, a large portion of the germinative vesiele 
is present, the spindle fibres having caused the wall on one side to 
disappear. The chromosomes are forming as independent bodies; 
not all are in the same stage of development, that is, some are 
smaller and take a lighter stain. The germinative vesiele has in- 
