No. 2.] BLATTA AND DORYPHORA. 309 
reduced to a small, somewhat crescentic body, which, unless its 
position has been marked, is easily mistaken for a yolk body, 
as it in no way differs from the surrounding yolk in ability to 
take up coloring-matters. Hence it happens that many investi- 
gators have supposed the insect egg to become enucleate at this 
time. The resemblance between a yolk polyhedron and the 
remains of the germinal vesicle is greatly increased by the gran- 
ular contents of both. In the germinal vesicle these granules 
are the comminuted remains of the large masses of chromatin so 
conspicuous in the young egg; in the yolk bodies they are albu- 
minous substances destined, like the other yolk materials, to 
become food for the protoplasm. At the very spot where the 
nucleus degenerated, viz. at the middle of the concave side of 
the egg, there appears in eggs almost mature (2.5-2.8 mm. long), 
a cluster of numerous chromatin granules, which I believe to be 
the same as those in the germinal vesicle, grown more conspic- 
uous by aggregation. Stuhlmann has figured several bodies 
like my Fig. 10, representing this aggregation which has pro- 
gressed considerably in the centre. These chromatin granules 
are probably uniting to form filaments preparatory to karyo- 
kinesis. The aggregation takes place in such a way that in 
eggs treated with Perenyi’s fluid a narrowly oblong mass of 
chromatin is formed, an appearance undoubtedly due to the 
fusion of the separate filamentous loops. The oblong mass is 
represented in Fig. 11. When the outlying granules have been 
added to it, and the achromatic fibrillze have made their appear- 
ance, the first polar spindle in the metakinetic stage is completed 
(Fig. 12). The axis of the spindle is directed at right angles to 
the surface of the egg, which is now mature though still enveloped 
in the follicular epithelium. In Fig. 13 the equatorial plate 
has divided transversely, whether by longitudinal fissure of the 
individual loops or not, I am unable to say, and the two masses 
of chromatin are on their way to the poles of the spindle. 
Arrived at the poles the masses become spherical, and the 
achromatic spindle fades away, while the outer sphere of chro- 
matin surrounded by a mass of protoplasm full of Blochmann’s 
corpuscles is almost constricted off from the egg to form the first 
polar globule. While this is taking place the egg is being freed 
from all its epithelium, except the cap at the cephalic pole, im- 
pregnated and placed in the capsule. The daughter nucleus of the 
