74 B. F. KINGSBURY 



that they are the thecal stroma cells of Graafian follicles that 

 have undergone or are undergoing degeneration. Saimont seems 

 to have based his conclusions upon the conditions in the theca 

 of the larger Graafian follicles. In atresia there are formed as 

 interpreted by him, hypertorphied interstitial cells. Reproduc- 

 tion of such cells shown in figures 13 and 14, however agree 

 rather with his figures of 'adult' cells. He published no figures 

 illustrating specifically this period, nor have v. Winiwarter and 

 Saimont as yet published descriptions or figures of the follicle 

 formation in the adult cat's ovary. If it were stated that the 

 thecal cells were intimately associated with the growth changes 

 of the maturing follicle and it were considered advisable to so 

 express this by ascribing to them a ''nutritive or trophic function" 

 there would, it seems to me, be little basis for a disagreement, 

 since there is much that indicates the importance of the stroma 

 in the growth processes within the ovary. The interstitial cells 

 might thus prove to be an expression of the arrest or abeyance 

 of a trophic function. 



WTiatever may perhaps be ultimately shown to be the exact 

 nature of the correlation, the phenomena of atresia show that 

 the interstitial cells stand as an expression of an altered metab- 

 olism associated with the (degenerative) processes that occur 

 within the atretic follicle, although the occurrence of free lipoid 

 in thecal cells of apparently normal follicles indicates both the 

 delicacy of the metabolic balance between theca and follicular 

 epithelium and that the appearance of free lipoid in the thecal 

 cells is not necessarily an indication of irreversible degeneration. 



The ovarian parenchyma (egg cells and indifferent or follicle 

 cells) is characterized by the high evident lipoid content of the 

 cells. Oocytes of the primary resting follicles show little or no 

 free lipoid with osmic acid as an indicator. The application of 

 a mitochondrial technique, however, reveals the numerous mito- 

 chondrial granules which undoubtedly represent lipoid in masked 

 or combined form. With the growth of the ovum numerous 

 globules of free lipoid make their appearance in the cytoplasm. 

 The follicle cells of normal follicles show little or no free lipoid. 

 Mitochondria are however present in abundance, particularly 



