FEMALE OKGANS OF GENERATION. 



861 



from below, which enclose little collections of cells. By both of these processes, little 

 cavities are formed, which contain a number of cells. In each of these cavities, we 

 observe a single, large, rounded cell, with a large nucleus, this cell being a primordial 

 ovum ; and, in addition, we have in the same cavity, other cells, which are the cells of 

 the Graafian follicle. The exact nature of the processes we have just described has been 

 studied in the fowl, but it is probable that the same kind of development occurs in mam- 

 malia and in the human female. 



From birth until just before the age of puberty, the cortical substance of the ovary 

 contains thousands of what are termed primordial follicles, enclosing the primordial ova; 

 and it is probable that, after the ovaries are fully developed at birth, no additional ova 

 or Graafian follicles make their appearance. The prevailing idea is, indeed, that the 

 great majority of these never arrive at maturity, and that they undergo atrophy at vari- 



FIG. 2T1 Portion of a sagittal section of the ovary of an old litch (Waldcyer.1 



a, ovarian epithelium; 6,6, ovarian tubes; c, c, younger follicles; f, older folliH.- : * ..jisrus orolip , ^th th< 

 ' ovum ; /; epithelium of a second ovum in the same follicle ; ff , fibrous mat -t thr MAde: *. pr 



follicle ; i, epithelium of the follicle (mombrana -r.-mulosa) ; *. <<.lh.ps.-l. atrop n-<l f. ,f tV,< o v in'-m r - 



cell-tubes of the parovanum. divided longitudinally and transvps-ly ; y. tubular , >rttl^ ^ *' ^ 

 theh'uin in the tissue of the ovary ; z, beginning of the ovarian epithelium close to tin- k 



ous stages of their development. According to the table of meMorementa given l.y AV S ,1- 

 deyer, the primordial follicles of the human embryo, at the seventh month, ai 

 about T&S to jfaf of an inch in diameter, and the primordial ova, from -nVv to ^ ol 

 inch. In the adult, the smallest follicles measure from about ^ to ^ of an nch, ai 



