SPERMATOGENESIS OF EUSCHISTUS abe 
are seen in the same cell (fig. 43), which then have a combined 
bulk equal to that of a single sphere of the same stage.“ These 
spheres become slightly browned by osmic acid but are not affected 
by nuclear stains, consequently they are readily overlooked; 
they are seen clearest in material preserved in Flemming’s solu- 
tion for twelve hours or more. In consistency they are nearly 
homogeneous, but contain small darker particles (figs. 40, 43-45) 
during the time of their growth. 
These spheres of spermatocytes have no conjunction with 
centrioles, nor do they touch the nucleus. They seem also to be 
independent of the idiozomes. Their relations to the mitochon- 
dria will be discussed later. 
During the histogenesis of the sperm another sphere arises 
and passes through a rather complicated history. This is a 
vesicle, first noticed at the stage of fig. 114 (Sp), and is very pale 
in color after all stains; it is represented as too dark in all the 
figures. Its genesis was not determined. At first it lies to one 
side of or even behind the nucleus (figs. 114-117), after which it 
moves in front of the nucleus (figs. 118-124, 126). Then it 
passes behind the nucleus again (figs. 125, 127-134), perhaps 
carried by the flowing of the cytoplasm along the axial thread. 
It possesses at the start a clearer central vacuole (figs. 114-117) 
later this larger vacuole becomes excentric and then lies in that 
part of the sphere that touches the nucleus (figs. 119-120, 122— 
134). Within this larger vacuole may generally be found a 
minute body which stains like the ground substance of the sphere 
(figs. 118, 122, 126-134), and is perhaps compe”eh'> to the acro- 
some of other animals. At the opposite end of the sphere a 
smaller vacuole develops (figs. 119, 124, 127-134); it is frequently 
difficult to see these two vacuoles plainly. Thus the sphere 
comes to lie behind the nucleus, and in a definite position, namely, 
15 All these relations have been described as found in a particular testis, no. 282, 
in which a single sphere is the rule. But in certain other testes multiple spheres 
are frequent, so that sphere relations vary in different individuals of the same 
species. It is remarkable that in the large spermatocytes of follicles 1 and 3 no 
spheres were found. 
