GRAAFIAN FOLLICLES. 273 



every month during a period of about forty years, it became 

 evident that the follicles must either be quite numerous, or be- 

 come successively and constantly developed. This led some 

 anatomists, who believed that, at the age of puberty, the ova- 

 ries contained, either partially or fully developed, all the fol- 

 licles that ever existed in these organs, to increase then* esti- 

 mates of the number of follicles. Sappey, from a series of 

 careful observations on this point, puts the number of follicles 

 at from 600,000 to 700,000.' We cannot but regard this esti- 

 mate as very much exaggerated. According to the table of 

 measurements given by Waldeyer, the primordial follicles in 

 the human embryo, at the seventh month, measure from -g-J-y 

 to ^-^ of an inch, and the primordial ova, from y^Vcr * 10*00 

 of an inch. 2 From what has been written on this point, it 

 seems difficult, if not impossible, to give an approximation, 

 even, of the number of follicles in the ovaries, but there cer- 

 tainly must be several thousands, many of which may never 

 become fully developed. 



Within the last few years, very important advances have 

 been made in our knowledge of the mode of development of 

 the ova and ovaries, which will be more fully considered here- 

 after ; but we must here refer to these points briefly, in order 

 to give a clear idea of the relations of the Graafian follicles, 

 in the different forms which they present under varied condi- 

 tions of development. 



The ovary appears, particularly from observations on the 

 development of the chick, very early in embryonic life, in the 

 form of a cellular outgrowth from the Wolffian body. Most 

 of its cells are small, but, as early as the fourth or fifth day, 

 some of them are to be distinguished by their large size, their 

 rounded form, and the presence of a large nucleus. These 

 cells are supposed to be primordial ova. In the process of 

 development of the ovary, some of the peripheral cells pene- 



1 SAPPEY, Traite d* anatomic, Paris, 1874, tome iv., p. 694. 

 8 WALDEYER, in STRICKER, Manual of Human and Comparative Histology, 

 The New Sydenham Society, London, 1872, vol. ii., p. 207. 



