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J. BRONTE GATKNBY. 
extruded and lies on the surface of the egg. The spindle of 
the second polar body is in the telophase and the chromo- 
somes seem fused. No aster or centrosomes could be seen. 
Around the neighbourhood of the forming polar body is a 
clear zone, and a little above the dumb-bell shaped figure are 
two large granules. I do not know exactly how these 
granules arise, but I think that they are possibly extrusions 
of the polar figures, for expulsion of granules from the nuclei 
can be observed in later stages. The fate of the polar bodies 
is not known. In Oophthora and Encyrtus they eventually 
degenerate (Hegner, 3a). 
The Stages between Formation of Polar Bodies and the 
Blastoderm. 
These are not described in the present paper ; through lack 
of material last spring I have been unable to get the stages. 
This spring I was able to procure a great deal more material, 
with which I hope to describe the early segregation of the 
germ-cells and the accompanying phenomena. 
The Blastoderm Stage. 
The material from the blastoderm stage onwards to the 
formation of the young larva is very complete. The germ-cell 
determinant at the posterior pole of the egg has, by the time 
of formation of the polar bodies, become more faintly staining, 
and considerably broken up (PI. 11, fig. 20, broken pieces 
P.P.). Such broken pieces come apart, and the whole deter- 
minant loses almost all affinity for stains of any kind. The 
exact time at which the determinant usually disappears is at 
present unknown, but very rarely one can find rather darkly 
staining patches in the germ-cells of the blastoderm stage, 
which may be the remains of the germ-cell determinant 
(PI. 12, fig. 36 G.) 
In PI. 11, fig. 12, the earliest blastoderm stage is seen in 
longitudinal section. The number of germ-cells is very diffi- 
cult to determine, for at about this stage the latter lose almost 
