296 WHEELER. [Vou. III. 
propria in the form of a tube tapering to capillary caliber at its 
upper extremity, which is attached to the pericardium. The 
lumen of the capillary portion is filled with protoplasm in which 
numerous small nuclei are imbedded. This portion of the ova- 
riole constitutes the germarium. The small nuclei differentiate 
at the lower end of the germarium, on the one hand into ova, 
which fill the widening lumen of the tube; and on the other, 
into flattened epithelial cells, which line the inner surface of the 
tube, and form the follicles inclosing the ova. There are about 
ten distinct ova in an ovariole, the lowest being the largest, and 
the most apical the smallest and most indistinct, those interme- 
diate regularly diminishing in size towards the apex. In Perz- 
planeta there are about three times as many ova in an ovariole; 
but there are only eight ovarioles in an ovary. The lower ova 
in both species are oval, and are surrounded on all sides by the 
epithelium, which has grown in between the separate eggs to 
complete the follicles. 
The follicular epithelium (Fig. 5) is composed of large, flat, 
polygonal cells, with lenticular nuclei which present an intri- 
cately coiled chromatin filament and a nucleolus of unusual struc- 
ture. The latter consists of an irregular mass, not stainable in 
carmine or methylgreen, and is regarded as plastin by Car- 
noy (9), who describes and figures very similar nucleoli in the 
egg-follicles of Gryllotalpa. The mass of plastin incloses a 
smaller mass of chromatin, or at least of a substance which does 
not differ in its reactions from the chromatin of the coiled fila- 
ment in the same nuclei. In eggs taken from the ovaries just be- 
fore maturity, when the epithelium is still firmly attached to the 
underlying chorion, almost all of the nuclei will be found 
rapidly dividing. Pieces of the epithelium from eggs of differ- 
ent ages were examined in normal salt solution, in methylgreen 
acetate held for a moment in the fumes of osmic acid, in Rabl’s 
chromformic acid, in Zaccharias’ acetic osmic acid; but no traces 
of an achromatic spindle, or of a regular arrangement of the 
nuclear filament, so characteristic of karyokinesis could be 
observed. I therefore conclude that we have here a case of 
akinesis or direct division. This conclusion is further strength- 
ened by the observation that the nucleolus divides first (Fig. 5 ¢), 
and the nuclear wall is constricted during division, an occur- 
rence exceedingly rare in kinetic nuclei, where the nuclear wall 
