No. 3.] ALLOLOBOPHORA FOETIDA. 493 
appearance of the cone is indicated by a lighter area at the 
periphery, this projecting beyond the periphery and the pro- 
jection continuing for some minutes after the cone is com- 
plete. The cone remains sharply differentiated from the rest 
of the cytoplasm during the constricting off of the first polar- 
body. The spindle is indicated by a lighter area clearly differ- 
entiated from the rest of the egg. The time occupied by the 
formation of the first polar-body has varied from 22 to 45 min- 
utes, and I am inclined to think that the artificial conditions 
hasten development; for in the above-mentioned cases (p. 484) 
where fresh cocoons were kept in the compost 14 and 2 hours, 
the eggs were still odcytes, 2d order. The changes in the 
shape of the egg during the process agree with those described 
by Vejdovsky ( (19), p. 51, Fig. 2) for Rhynchelmis, except that 
as the constricting progresses, the periphery of the egg at 
that point flattens, and finally becomes concave, the polar- 
body resting in the center of the concavity. At this stage, 
the membrane over the polar-body is so taut that the latter is 
often somewhat flattened by its pressure, suggesting that this 
pressure of the polar-body against the periphery of the egg 
may be at least partly responsible for the above-mentioned 
concavity. The phenomenon as seen in the living egg accords 
entirely with my observations on fixed material. A small 
part of the cytoplasm appears to be pushed out by the spindle, 
the latter first moving to the periphery and then projecting 
beyond it until its equator has reached the periphery of the 
egg, when the process of constriction takes place. The time 
occupied by the formation of the second polar-body has varied 
from 20 to 60 minutes, the two phenomena (the formation of the 
first and second polar-bodies) being similar. In each case a 
lighter area first appears at the periphery, the egg slowly elon- 
gates from this point, and the process terminates in the comple- 
tion of the polar-bodies.!_ Preserved material shows that the first 
polar-body divides by mitosis. Vejdovsky (19) has figured this 
in Taf. XIII, Fig. 8. Before, during, and after the formation 
1 One expression of a pathological condition of the egg is a constricting off at 
the periphery of small portions of its cytoplasm, and care is necessary to avoid 
confounding these with the polar-bodies. 
