634 
Wm. S. Marshall 
the chambers of tbis same size a similar structure is noticed, the prin- 
cipal variations being in tbe greater width of the onter laver of tbe 
oöcyte. Tbis peripberal layer is composed of tbe matter last secreted 
by tbe epitbelium; it is forrned by a gradual secretion which may 
increase or decrease in amount witb the greater or less activity of 
tbe cells. Brandt (2) in Periplaneta and Gryllus observed a layer, 
“Zickzacksaum” at the ends of the epithelial cells which he describes 
somewhat ditferently: ..Diese Enden lösen sich gleichsam in einen 
Schopf von Protoplasmastreifen auf, welche selbst aus Körnchen be- 
stehen und in den Dotter hineinragen.“ In the epithelial cells of 
any of these chambers dividing nuclei are auite abundant; the mitotic 
figures are generally near the basal end of the cells. 
In later stages the seeretory activity may be indicated in other 
ways than that just described. After the oöcytes have reached a 
larger size the epithelial cells do not, as in the younger stages, all 
appear active but these latter are scattered singly or in groups throughout 
the follicular epitbelium so that resting and active cells are found side 
by side (Figs. 15 and 16). 
Another way in which the seeretory activity of the cells was 
noticed, or, that some closely allied process was going on, was the 
presence, in many of the cells, of a darkened cvtoplasm in that part 
of the cell nearest the oöcyte. In many cells the cvtoplasm at the 
free end was considerably darker than that in the basal part.* All 
gradations from cells in which the cytoplasm in all its parts stained 
similarly to those with verv much darker free ends, could be found. 
At the sides of each nucleus there was generally so little space 
between it and the boundaries of the cell that the condition of the 
cytoplasm in tbis region could not, in most cells, be ascertained. 
Between each end of the nucleus and the adjacent end of the cell 
there was a considerable amount of cytoplasm; in very many cells 
that at the free end was darker and denser than that at the base 
(Fig. 15). In many of the older chambers the cytoplasm of the free 
end also contained a number of vacuoles (Fig. 13) or showed striati- 
ons, or both (Fig. 19). The shape of the nucleus in the walking-stick 
and the small surface facing the oöcyte may account for the fact that 
all the cytoplasm between the end of the nucleus and the oöcyte was 
darkened and that there was no small darkened area, Kokschelt 
(13), Mgllisox (20); tbis with the small amouut of cytoplasm at the 
sides of the nucleus could also account for not distiuguishing a ,.Zona 
perinucleare”, Giardina (7), if such was present. 
