Sixteenth Annual Meeting. 141 



The nuclei are lenzitoid and extremely flattened. Seen from above, they present 

 various subcircular outlines, which are often asymmetrical. The nucleoli are compara- 

 tively small, though well defined, and are often excentric. 



In the suspensory ribbons, which are simply elongations of the ovary wall, the spar- 

 ingly present nuclei are so distributed as apparently to forbid a cellular structure — sev- 

 eral nuclei being often huddled together in one part of the ribbon, while in adjacent 

 intervals there are none at all. 



The oviduct is placed somewhat nearer the posterior than the anterior end of the 

 ovary, its walls being composed of broadly columnar epithelium, and its ovarian end be- 

 ing inflated to form a reeeptaeulum seminis, whose junction with the ovary, being in the 

 line of the germogen, divides the latter into an anterior and a posterior arm. 



Whether of syncytial or cellular origin, numerous germinal cells may be seen in the 

 germinal tract of the Porcdlio ovary, and since these appear to originate from indefinite 

 germ-like bodies, the term germogen may be conveniently retained. 



In the smaller germinal cells the nucleus is relatively small, sometimes even indistin- 

 guishable, but in those which are destined to become eggs, the nucleus grows more rap- 

 idly than the cell-body, and is at length relatively large. Prior to the escape of the 

 germinal cell into the general ovarian cavity, its nucleus is seen to be surrounded with a 

 densely granular zone which, spreading outwardly as the cell grows, at length reaches 

 the cell-wall. 



In the course of this growth, the nucleolus sometimes divides into two or three simi- 

 lar and smaller nucleoli, and the eggs themselves become invested with a follicular epithe- 

 lium. This consists of small ovate to cylindrical cells, arranged in columnar fashion in 

 a single (or in part double) layer, closely investing each ovum, the polygonal spaces 

 thus temporarily left being usually occupied by a few isolated cells similar to those of the 

 follicles. The entire follicular structure is definitely limited by a layer of cells quite 

 like that which constitutes the several follicles, and, in fact, partly composed of the 

 outer portions cf those follicles. The cells destined to form the follicles are at first 

 loosely scattered in the region about the ovum to which latter it would seem that they 

 migrate later. Their final origin was not determined. As they attain maturity, the ova 

 become more or less polygonal by pressure and are then usually arranged in two rows, 

 with rarely a part of a third completely filling the ovary. Some of them undergo ret- 

 rogressive development, the function of such retrogression being probably connected 

 with nourishing the true ova, this being partly accomplished also by the follicular epi- 

 thelium, and perhaps further aided by the product of a peculiar gland-like streak* which 

 extends along the side of the ovarian tube opposite that which the germogen occupies, 

 appears to be of protoplasmic nature, though of yellowish brown color, contains numer- 

 ous scattered granules and larger irregular and ill-defined masses, and possibly represents 

 a functional vitellarium. 



In this rapidly growing condition of the ovarian egg the germinal vesicle is central 

 in its position, and relatively large as compared with the ovum. After the ovum has 

 attained its growth, the germinal vesicle leaves the center, becoming relatively smaller 

 and at last reaches the surface of the ovum. There is apparently a narrow liquid zone 

 between the outer limit of the protoplasm of the egg and the chorion, and I have not 

 observed the nucleus to pass entirely across this zone so as to be in actual contact with 

 the chorion. I have, however, observed it to push out into this space, the projected por- 

 tion still covered with a thin layer of granular protoplasm, and thus making a consider- 

 able protruberance. Whether this was really what it seemed to be, viz., a preliminary 



*This streak was noticed only while the ova were in process of maturation. While cellular struct- 

 ure, such as may be observed in most glands, was not made out, it may have been present, obscured by 

 the cell products, as the streak was not studied in section. I first thought the structure to be of a detriia, 

 nature, as further Investigation may yet prove it to be. 



