298 WHEELER. [VoL. III. 
ters, sometimes singly. With a higher power the tube of each 
funnel is clearly visible as a thin canal which dilates rapidly 
into the large oval aperture on the outer face of the chorion. 
The narrow tube is sometimes fully as long as the large orifice. 
The micropylar perforations are all directed from the germa- 
rium to the vaginal pole of the egg. Hence a line, the hypo- 
thetical path of the spermatozoén, drawn through one of these 
oblique micropyles, and continued into the egg, would strike 
the equatorial plane. The female pronucleus, as we shall see 
further on, moves in this plane. 
The micropyles of Per7planeta, first described by Kadyi (23), 
do not differ essentially from those of Blatta. In Periplaneta 
the hexagonal pattern is continuous over the micropylar area. 
The large micropyles, which are more yellowish than the sur- 
rounding chorion, are thick walled and not regularly oval, as in 
latta, but oblong or subpentagonal. The tube is shorter and 
terminates on an hexagonal area. Sometimes the micropyles 
are very close together and seem to overlap. 
I have repeatedly sought in vain for a vitelline membrane in 
the eggs of latta. Blochmann (5) had no better success. It 
may exist, but it must be exceedingly thin and inseparably glued 
to the inner lamina of the chorion. 
The colleterial glands of A/atta are like those which Huxley 
(22) and Kadyi (23) have described for Pertp/aneta, a number of 
long, blind tubes opening into the vagina. They furnish the ma- 
terial for the capsule, viz.: chitin and large crystals of calcium 
oxalate. In Alatta these glands are glistening white till the time 
of oviposition approaches, when they assume a yellow tint, and 
the octahedral crystals are seen imbedded in a viscid sub- 
stance which fills their lumina. This viscid substance is sol- 
uble in potassium hydrate, and is consequently not chitin. 
When excreted to form the odtheca, it slowly hardens, deepens 
in color, and becomes insoluble in potassium hydrate. Light 
has nothing to do with this change, which is possibly produced 
by the oxygen in the air. It is the same change which is 
undergone by the cuticula of the insect itself immediately 
after ecdysis. 
I have made a few observations on the oviposition of Platta 
germanica, similar to those published by Kadyi (23) on Pert- 
planeta orientalis. 
