Relation between Nucleolus and Chromosomes. 43 
trustworthy clue as to the manner of the reduction of the chromosomes. 
The slight evidence that synizesis and the maturation divisions give seems to 
indicate that Asterias forbesii agrees with the parasynaptic type of reduction. 
Up to the period when the oOdcyte has reached about half its full-grown 
size the cytoplasm is wide-meshed and coarsely granular, the granules 
usually lodging at the intersections of the meshwork. With the iron hema- 
toxylin and orange G combination of stains, the cytoplasm stains dark blue 
or in cases where the staining action of the orange G is prolonged the 
resulting stain is dark brown. In subsequent stages the cytoplasm is always 
stained a lighter or darker orange color. This difference in color reaction to 
similar staining combinations between the cytoplasm of the growing and full- 
grown oocyte is very striking and due, I believe, to the presence of a great 
amount of yolk or to the fore-products of chromatin formation in process of 
transportation to the nucleus and nucleolus. There is a progressive and 
approximately proportional increase in volume of nucleolus, nucleus and cell- 
body through the growth-period. 
Auerbach’s stain reveals a similar difference in staining reaction be- 
tween the cytoplasm of the growing and that of the full-grown odcyte. 
In the latter the cytoplasm has a deep-red (fuchsin) color, while that of the 
smaller odcytes has a grayish or bluish-red color, showing undoubtedly the 
influence of the methyl green constituent of the stain in its reaction to the 
forming chromatin. Similar observations have been reported by Griffin in 
the case of the egg of Zirphea. 
The ovaries upon which the above observations are made were gath- 
ered during July and August. A study of ovaries gathered during the last 
week in December confirmed in every respect the description given above of 
ovarian material. In both cases the sparsity of transition stages and the large 
number of apparently full-grown odcytes is very striking. It appears that 
Asterias has no special periods of reproductive activity, as is the case with 
most of the Metazoa, but produces ripe eggs perpetually. 
THE FULL-GROWN PRIMARY OOCYTE. 
The full-grown primary odcyte of spherical outline has a diameter of 
about 100 microns. The nucleus of such an odcyte has a diameter of from 
one-half to somewhat less than one-half the diameter of the cell (50-40 
microns). The nucleolus varies in size from one-fourth to one-fifth the 
diameter of the nucleus. The nucleolus (or germinal spot) invariably takes 
an eccentric position as regards the germinal vesicle (figs. 37, 38, 39). A 
generalization to this effect for many kinds of eggs was made by Mont- 
gomery in 1898. The eccentricity of the nucleolus showed no regularity in 
respect to any particular side of the nucleus or even to the wall of the 
alveolus (figs. 38, 39). The nucleus also often holds an eccentric position 
as regards the egg-cell, though not infrequently it is located centrally (figs. 
