INTERSTITIAL CELLS OF MAMMALIAN OVARY 71 



and Saimont ('08) ; but I believe when closely examined, the 

 evidence for this interpretation is not only inconclusive, but on 

 the contrary points in quite the reverse direction. This will 

 be discussed presently. 



Before taking up the question of the interpretation of these 

 cells, I wish to confirm the conclusion of Saimont and others 

 that these cells are transcient structures in the ovary; that they, 

 as interstitial cells, possess no permanency; that they come and 

 go. This conclusion would be a priori self evident from their 

 mode of origin in the adult ovary. I further agree with Saimont 

 that their fate is not one of degeneration, but that they revert 

 to the cell type out of which they were developed, that is, the 

 stroma cells. Saimont accordingly recognizes (a) young inter- 

 stitial cells, (b) transitional forms, (c) adult interstitial cells, (d) 

 degenerated interstitial cells; i.e., those reassuming their char- 

 acter as stroma cells, and (e) hypertophied cells. These stages, 

 he finds to be somewhat characteristic of the three periods that 

 he recognizes. Thus the stage (a) he thought limited to the 

 first period; the stage (b) occurs only after birth, etc. It might 

 be pointed out, however, that, obviously, from their very evi- 

 dent continous formation, when once fully established, essen- 

 tially all stages must exist in the ovary at the same time — as in 

 the adult. The distinction of stages is but a matter of conven- 

 ience in description, and the terms are likewise of but meta- 

 phoric value. 



The interstitial cells thus possess no morphological individu- 

 ality and hence do not, strictly speaking, deserve recognition as 

 a distinct kind of cell. They are stroma cells, which under cer- 

 tain conditions, undergo changes, the most striking and charac- 

 teristic histological alteration being the accumulation of lipoid 

 granules within their cytoplasm. Apparently with the passing 

 of these conditions thej' again become stroma cells. 



In considering the question of the interpretation of these cells, 

 therefore, the above definition must be kept in mind, since what 

 may be true of a stroma cell need not necessarily be also true of 

 an 'interstitial cell.' This is particularly true of the 'trophic 

 function' interpretation as advanced by Plato and accepted by 



