846 RECORD OF CURRENT RESEARCHES RELATING TO 



of embedded germ epithelial cells, many of which groups are not 

 completely cut off from the germ eiiithelial layer by the young 

 ovarian stroma. Such groups of germ epithelial cells, in various 

 forms, are met with in all ovaries, but have no importance what- 

 ever as tubular structures. In the human child's ovary numerous 

 furrows, or clefts between irregularities of the general surface, are met 

 with. Sections through these furrows and clefts produce the appear- 

 ance of the germ epithelium (pseudo-epithelium, Balfour) having passed 

 downwards into the ovary in the form of tubular open jiits, as was 

 described by Waldeyer and his predecessors. No real tubular struc- 

 tures from which Graafian follicles are formed exist in the mam- 

 malian ovary at any stage of its development. Graafian follicles are 

 formed only in one way from the beginning of the ovary to the end 

 of its existence. 



The youngest connective tissue of the stroma, in the form of 

 offshoots of jelly-like protoplasm, surrounds and embeds large and 

 small groups of germ epithelial cells. A single germ epithelial cell 

 may be completely surrounded by this young connective tissue. 

 "When this takes place the germ epithelial cell rapidly grows and 

 becomes a primordial ovum. Each individual cell in a group of 

 epithelial cells, surrounded by the young ovarian stroma, shows a 

 similar tendency to become a primordial ovum. All the grouj)s of 

 develoi)ing germ-cells or cell-nests in the ovary are broken up into 

 still smaller cell-nests by the ever advancing young connective tissue, 

 until, at last, individual cells in the cell-nests become comj^letely 

 surrounded by the youngest connective tissue. When an individual 

 germ-cell becomes surrounded by the young connective tissi;e, at the 

 same time, and as part of the j^rocess, the Graafian follicle begins to 

 be formed. Whenever the young jelly-like connective tissue appears, 

 in its substance nuclei, generally fusiform at first, make their appear- 

 ance. These nuclei may be always seen in contact with the yolk 

 substances of the primordial ova. The follicle cells are derived from 

 the nuclei which lie in contact with the protoplasm or yolk substance 

 of the developing ova. This takes place in all parts of the ovary 

 wherever cell-nests are formed. The follicle cells thus originate 

 from the cells of the ovarian stroma, and not from the germ epithelial 

 cells. In the mammalian ovary at birth the most advanced ova are 

 met with deep in the ovary, and not in passing from without inwards, 

 as described by some observers. In a ripe Graafian follicle the 

 stroma cells outside the membrana propria folliculi become converted 

 into cells exactly similar to the true follicle cells, and it is possible to 

 trace the oi'dinary stroma cells outside the follicle through all stages 

 of development into cells resembling the follicle cells, the observation 

 affording a most conclusive proof of the origin of the follicle cells 

 from the ordinary cells of the stroma. 



With these results it will be interesting to compare those of 

 Mr. Balfour ; he, likewise, says " The whole egg-containing part of 

 the ovary is really the thickened germinal epithelium." " Pfliiger's 

 egg-tubes are merely trabeculae of germinal epithelium, and have no 

 such importance as has been attributed to them." So again, as 



