270 FRANZ SCHRADER 
MATURATION IN THE EGG 
The earliest stages of maturation are found in the adult female, 
the abdomen of which is best fixed and sectioned entire. Dur- 
ing the growth stages, the nucleus is situated at the center of the 
egg. Its black nucleolus, surrounded by an unstained proto- 
plasmic area, and its definite nuclear wall make it readily distin- 
guishable from the mass of densely staining yolk granules which 
fill the egg at this time. The prophase offers nothing that is 
new, the chromatin going through the various phases of chromo- 
some formation while the nucleus approaches the central periph- 
ery of the egg. Here the nuclear wall disappears, and further 
developments take place in a clear irregular area of protoplasm, 
as in many other insect eggs. 
Tetrads were found in a few of the preparations, their appear- 
ance resembling those of typical Homoptera as described by 
Miss Boring (’07). They are eleven in number, and their further 
condensation gives rise to the rounded deeply staining bodies - 
which occur in equatorial plates of the first division. Although 
differing only very slightly in size, their arrangement in the plate 
seems to be a very definite one, and is the same in all eggs. Nor- 
mally the metaphase is the farthest stage reached while the egg 
is in the body of the insect, but occasionally early anaphases 
are found in females which have been prev puter from laying for 
a short period. 
In the first division, each of the chromosomal bodies undergoes 
division and eleven dyads go to each pole. The outer group of 
these, or first polar nucleus, is not extruded, but remains close 
to the periphery. Both the polar nucleus and the egg nucleus 
enter immediately on a second division. The division of the 
former appears to lag somewhat behind, as the irregular arrange- 
ment of the dumb-bell-shaped dyads in figure 7 and in other 
preparations would indicate, but two daughter bodies are formed 
from it in any case. The division of the nucleus proceeds nor- 
mally. The resulting second polar nucleus, like the first now 
divided, is not extruded, but remains close to the periphery, 
where all three ultimately disintegrate, while the reduced egg 
nucleus, with its eleven univalent chromosomes, travels toward 
the center of the egg. 
