THE SEXUAL ORGANS. 657 



0-0065-0-008 of a line in size, ^YitIl a germinal spot of 0-001-0-0015 of 

 a line, from the epithelium, to ^Yllich at first it was closely applied, and 

 forcino- it into the centre of the follicle. When this has attained the 

 size of 0*02 of a line, a membrane in close apposition with the memhrana 

 granulosa, and surrounding the germinal vesicle and the whole contents 

 of the follicle — the vitelline membrane — becomes evident ; which is re- 

 garded by all authors as a secondary formation, although it probably 

 exists, even in the very earliest rudiment of the follicle, as an extremely 

 delicate membrane, closely surrounding the germinal vesicle. At first 

 excessively delicate, and scarcely perceptible, the vitelline membrane, 

 when the follicle has increased in size and contains more fluid, becomes 

 more distinct, owing to its removal from the wall of the follicle, and 

 rapidly thickens. In follicles of 0-04-0-05 of a line, the ova are per- 

 fectly distinct and disproportionately large, with a delicate zona pellu- 

 cida, and still lying very close to the walls of the follicle. The further 

 development is apparent of itself; and I will only remark that, in the 

 new-born child, follicles visible to the naked eye will be more rarely 

 found ; whilst such make their appearance even before puberty, although 

 they undergo no considerable development before that period. 



According to what has been said, the mode of origin of the Graafian 

 follicle ranks in every respect with that of the tubular glands. The for- 

 mer is an agglomeration of cells, at first, perhaps, without cavity or con- 

 tents, to which the structureless membrane is added, not by the coales- 

 cence of the outermost cells, but probably as an excretion from them, 

 and thus is formed the follicle, which therefore exactly corresponds with 

 a closed gland-vesicle, or a section of a tubular gland canal. How the 

 germinal vesicle, and the vitelline membrane arise, is doubtful ; the for- 

 mer is either a nucleus of new formation, originating in the minute cavity 

 of the follicle, about which a certain amount of vitellus is subsequently 

 collected, the cell, or vitelline membrane not being formed until after 

 this, from a sort of cell formation "around portions of contents;" or 

 the whole ovum, with the germinal vesicle, is nothing else than the cen- 

 tral cell of the primordial rudiment of the Graafian follicle, and conse- 

 quently co-existent with it. In any case it corresponds to a cell, and the 

 germinal vesicle is nothing but the cell-nucleus. 



With respect to the ijhjsiological conditions of the mature, female 

 sexual organs, much has already been remarked in the preceding pages ; 

 and it will, therefore, here be sufiicient to say something about their 

 movements and secretions. In the ovaries, whose stroma frequently pre- 

 sents a deceptive appearance of muscularity, I have in vain sought for 

 muscles, with nitric acid of 20 g, although in recent preparations micro- 

 scopical appearances are occasionally obtained, which one is inclined to 

 explain as belonging to that tissue. That the oviducts are capable of 



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