Quain's elements of anatomy . ollicle proceedoriginally from the germ-eijithelimn along with the primitive ova. ByFoulis, on the other hand, the origin of these ceUs has been attributedto an enclosure and diflFerentiation of the cells of the ovarian stroma,while KoUikers observations have led him to adopt the view that theyproceed from the cellular contents of tubes which are connected withthe Wolffian body, and remain for a time as vestiges in the base of theovary (paroophoron ?). But the observations of Ludwig (Xo. 59)and Balfour (Xo. 62) seem to show very decidedly that in the lowervertebra
Quain's elements of anatomy . ollicle proceedoriginally from the germ-eijithelimn along with the primitive ova. ByFoulis, on the other hand, the origin of these ceUs has been attributedto an enclosure and diflFerentiation of the cells of the ovarian stroma,while KoUikers observations have led him to adopt the view that theyproceed from the cellular contents of tubes which are connected withthe Wolffian body, and remain for a time as vestiges in the base of theovary (paroophoron ?). But the observations of Ludwig (Xo. 59)and Balfour (Xo. 62) seem to show very decidedly that in the lowervertebrates the epithelial lining of the primitive follicle is the direct])roduct of cells which, like the ova themselves, proceed from the germ-epithelium. And thougii it must be admitted that in the humanembryo there are appearances favourable to the view taken by Foulis, thewriter of this is induced from his own observations in the human ovaryand that of several mammals now to give a preference to the opinion ofWaldeyer. Fig. ^<^^ I Fig. 808.—Section of the ovary of a newlt-born child. Highly magnified (Waldeyer). a, Ovarian or germinal epithelium ; b, formation of an ovarian tube ; c, c, primordialova lying in the germ-epithelium ; d, d, longer tube becoming constricted so as to formnests of cells ; e, e, larger nests; /, distinctly formed follicle with ovum and epithelium |g, g, blood-vessels. In the earliest stages of ovarian development, and for a considerable timeafterwards, the germinal cells of the genital ridge undergo a remarkable multi-Ilication, and many of them while still close to the surface, become much largerthan the rest, and assume the appearance of primordial ova ; the nucleus expand-iiig into the germinal vesicle, with a distinct nucleolus (or macula) formed withinit. and the external protoplasm increasing greatly to form the vitellus or yolk,but, at first, without any enclosing membrane. As these ovigerms increase in number and size they retire from t
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