398 
CniYOMATSU ISHIKAWA. 
branches. Like that to the right lobe, one of these taking the 
backward course runs through the entire posterior part, while 
the other running anteriorly, soon sinks into the substance of 
the ovary. 
In front of the heart two other branches are given off, from 
the antennal arteries. Each of these soon divides into three 
main branches : the anterior, the posterior, and the median or 
lateral. The anterior runs along the whole length of the 
anterior half of the ovary, the posterior divides into fine 
capillaries, and penetrates into the interior of the ovary, while 
the lateral unites with its fellow of the opposite side. There 
are no large vessels on the lower side of the ovary. 
In some specimens, the sternal artery runs over the left lobe 
of the ovary, giving off a branch to it, while the right lobe 
was supplied with one given off directly from the heart. 
The inner set of layers in the ovarian walls consists of (1) a 
fine structureless membrane (fig. 10, mb.), and (2) a layer of 
pyramidal epithelial cells. This epithelial layer will be spoken 
of as the “ internal ” epithelial layer in contradistinction to 
the one already described, which will be called the “external.” 
The internal epithelial cells exist only over the vitellogen, the 
w r alls of the germogen being devoid of the epithelium properly 
so called. The epithelium cells (figs. 8, 9, and 10, fe.) are in 
general somewhat elongated, and are furnished with a finely 
granular nucleus, in which a nucleolus can be detected. The 
ceils measure about 0'2 mm. in length and 0 08 mm. in 
breadth, and the nuclei are about one tenth the size. The 
epithelium, together with the structureless membrane, enter 
into the ovary and surround the eggs in the vitellogen, form- 
ing thus a sort of a follicle (figs. 8, 9, 10, 13, fe.). 
The wall of the oviduct shows the same structure as that of 
the ovary itself, excepting that the superficial epithelial cells 
are, as already stated, decidedly smaller than on the ovary 
proper, being only about one third. 
It appears thus that the wall of the ovary and oviducts 
consists (1) of a connective-tissue layer; (2) of an external 
epithelium ; (3) of stroma ; (4) of blood space ; (5) of a struc- 
