No. 2.] BLATTA AND DORYPHORA. 367 
As the granular yolk polyhedra of the ventral portion of the 
egg are much smaller than the homogeneous ones of the in- 
terior, there is more protoplasm in the ventral part of the egg. 
The internal portions crumble very easily in sectioning, and 
I am hence inclined to think that very little or no protoplasm 
extends in between these bodies from the periphery. Thus we 
see that the distribution of the protoplasm, as well as the yolk, 
is in accordance with the position of the future embyro. Later, 
when cells appear in the egg, their amceboid cytoplasm con- 
sists of evenly granular protoplasm, faintly stainable in borax 
carmine. 
Karyography of the Egg.—In studying the changes in the 
nucleus, it has proved to be impossible to preserve the finest 
cytological details, since the ovarian eggs of lata, like the 
eggs of the Orthoptera in general, are not easily sectioned un- 
less hardened in Perenyi’s fluid, as the yolk is exceedingly 
friable. Perenyi’s and Kleinenberg’s fluids do not preserve the 
karyokinetic figures perfectly, but cause the loops of chromatin 
to fuse in masses. On the other hand, the achromatic spindles 
are often beautifully distinct. Any discrepancy between Bloch- 
mann’s figures of the polar globules and mine, is probably to 
be attributed to a difference in the use of reagents. 
In young and transparent ova taken from the middle of the 
ovariole, the nucleus is seen to’have reached the acme of its 
development in volume. It is a large spherical body, more 
highly refractive than the surrounding cytoplasm. Its fluid 
contents, the karyoplasm, is distinctly separable into two sub- 
stances, a liquid karyochylema and an achromatic (plastin ?) 
reticulum. In the meshes of the latter is suspended a third 
substance, the deeply stainable chromatin, in one large and sev- 
eral smaller masses, or in several small irregular particles de- 
rived from the former by disintegration. The nuclear wall is 
very distinct. Whether it is a membrane or merely a peripheral 
inspissation of the karyoplasm is uncertain. When ovarioles 
are treated with Fol’s picrochromic acid or Merkel’s chromplat- 
inum solution, the whole nucleus contracts and leaves a menis- 
coid cavity between itself and the cytoplasm, though it still 
preserves its distinct and evenly spherical contour. 
In all the following stages the egg, having become opaque, 
must be studied in sections, and the history of the nucleus con- 
