L. E. Robinson and J. Davidson 
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the anatomy of the genital organs as they appear in the mature adult, 
shortly after engorgement. In the female, particularly, different parts 
of the genital system are, more or less, always in a state of change, and 
though the gross anatomy is not much affected thereby, the study of 
the histological structure of the ovary, the walls of the uterus and the 
oviduct, is rendered exceedingly difficult by the fact that degenerative 
and regenerative phases may be exhibited simultaneously in various 
regions of the genital tract. 
The observations which were made in connection with the anatomy 
of the alimentary canal (Part II, p. 235) apply here with even greater 
foroe, and it would necessitate the collection of a large supply of care¬ 
fully prepared material, the history of which was definitely known, in 
order to work out these phases of development in a satisfactory manner, 
a fact that we did not sufficiently realise when preparing the material, 
the study of which has furnished the matter for this paper. 
The Female Genital Organs. 
The female genital organs are comprised of: 
1. The Ovary. 3. The Uterus. 
2. The Oviducts. 4. The Vagina. 
5. Gene’s organ. 
The Ovary. 
Plate XXVI, figs. 1-5 (see also Part II, Plate XIV ov.). 
The ovary (ov.) is situated in the posterior half of the body, its median 
portion lying between the rectum in front and the foremost columns of 
the postero-inedian dorso-ventral muscles behind ; it is covered dorsally 
by the postero-lateral coecal lobes of the stomach and its ventral 
surface rests upon the anterior portion of the rectal sac. 
The organ consists of a broad strap-like tube with thick walls, 
which lies transversely across the body, its entire length measuring 
approximately one-half of the body width. The ovary frequently 
appears to be twisted and crumpled by the pressure of the superposed 
alimentary coeca. The external surface is densely studded with small 
spherical bodies—the immature ova. 
In transverse sections of the ovary, its wall is seen to be formed of 
a thick epithelium composed of cells of variable size and appearance 
which rest upon a thin structureless basal membrane. From this 
