Nov33), 2HZ £2GG OF ALLOLOBOPAORA FOETIDA. 481 
The nucleoli, which are very pronounced in the germinal 
vesicle of the egg, prepared to leave the ovary, can be seen 
during the formation of the first maturation spindle, as bodies 
of varying sizes distributed through the cytoplasm of the egg. 
They appear first close to the spindle, and later some are seen 
very near the periphery of the egg (Fig. 1). These bodies 
were at first regarded by me as nucleoli; but later I was not 
satisfied with this interpretation, and I am greatly indebted to 
Dr. Wheeler for information which decides their significance. 
Upon this point he has generously given me the result of his 
unpublished work on the egg of Myzostoma. 
After the first polar body has been constricted off, the eleven 
chromosomes remaining in the egg, move to the extreme lower 
pole of the spindle ; and in one preparation they there assume 
the same form and arrangement that they show after the second 
polar body has been formed. In this case the entire achro- 
matic portion of the second spindle must be a new formation. 
Fig. 6 shows the form and arrangement of the chromosomes 
after the second division, when the female pronucleus is enter- 
ing upon the resting condition. Each chromosome has now 
assumed the form of a vesicle, with the chromatin occupying, 
in most part, the periphery of the vesicle, and examined from 
any point of view, they present the same appearance as indi- 
cated in the figure. The fact that exactly this same condition 
is seen after the formation of the first polar body, recalls 
Boveri's (3) statement that the claim has been made by 
Garnault and others that there is, in some cases, a resting 
stage between the first and second divisions. Whether this 
is a constant stage in the maturation of this egg, or an excep- 
tional case, cannot be determined without the study of more 
material. This formation of chromatic vesicles, leading to a 
resting condition, offers a confirmation of the views of Van 
Beneden (1) in the case of Ascaris. 
Pronuclet, Fig. 7. The majority of eggs contain only two 
pronuclei, though apparently perfectly normal eggs may con- 
tain three or four. The size of the average egg at this stage 
of development is about .o2 mm. smaller than the egg of 
the stage represented in Fig. 1. I have found no distin- 
