1346 



CRUSTACEA. 



through its whole extent. Where exserted, it is very distinctly 

 divided by membranous partitions into narrow compartments, each 

 containing an egg, though not quite filled with it. The eggs in the 

 anterior slender portion of the oviduct are oblong and uniformly trans- 

 parent. As they increase in size, they present a clouded appearance, 

 and become divided into two parts, the inner of which appears clouded 

 and composed of albuminous globules (fig. q). 



In the advanced eggs at the extremity of the ovary, we observed, 

 in one instance, that there were two distinct eyes at their outer extre- 

 mity; they were approximate, but not situated on the same black 

 ground. 



In addition to the ovaries above described, there is a pair of organs 

 in the abdomen, connected with the system of generation. They are 

 straight, flat-cylindrical organs, usually as broad as the external ovi- 

 duct, and lie along the central portions of the abdomen. At the 

 -lower extremity, they are connected with the oviduct a short distance 

 above the vulva, and at the upper, they terminate in a cul-de-sac. 

 They contain a single series of transparent flattened globules (fig. q), 

 occupying, like beads, their central line, and in width about one-half 

 the width of the ovary. These false ovaries, when torn or cut, do 

 not emit an albuminous fluid, like the true oviducts, but appear to 

 have a gelatinous consistence. They are as much developed in the 

 young as in the old females. 



The eggs in females of the same size present very different degrees 

 of development. We have seen full-grown individuals with no eggs 

 in the abdomen, and consequently, instead of the swollen appearance 

 usual in the adult female, their abdomens could scarcely be distin- 

 guished from those of the male sex. Occasionally, very young indi- 

 viduals have had external ovaries ; the smallest observed was scarcely 

 one-sixth of an inch long. May we not infer from this, that a single 

 coition is sufficient to impregnate the individuals of at least one suc- 

 ceeding generation ? 



A few instances have come under our notice, of a very extraor- 

 dinary irregularity in these organs. The extremity of the false ovary 

 has been seen hanging externally in the place of the regular external 

 ovaries, and neither eggs, nor the internal oviduct, were discoverable 

 in the interior on that side. Moreover, the corresponding ovary near 

 the stomach was discovered with difficulty, and appeared like a folded 

 empty sac. At the same time the ovary and the ovarian tube on the 



