ANATOMY AX I) HISTOLOGY OF THE OVARIES 543 



as they do, direct continuity between the intercellular spaces, lymphatics, 

 and veins (Figs. 2 and 4); and his further conclusion, that this secre- 

 tion is equivalent to that formed by the lutein cells, cannot be dismissed 

 lightly, in view of the statement (still unsubstantiated) that heat and 

 menstruation occur in the absence of corpora lutea and that certain 

 changes which usually follow spaying may be inhibited by grafts of tissue 

 devoid of corpora lutea. The only weak point in his work, in my judg- 

 ment, is the lack of detailed information relating to the microchemistry of 

 the material which he observed in the intercellular spaces, lymphatics, and 

 veins. Kingsbury ('14) gives a caustic criticism of the general conclusion 

 that the secretion is lipoidal. Unfortunately we have as yet no means of 



IcP 



Fig. 3. Interstitial cells of the ovary of a young bat fixed in Benda's fluid and 

 stained with safranin. Note the formation of clear vesicles of secretion antecedent 

 within the darkly stained fat globules. After 0. Van der Stricht. 



knowing just how far the human condition approximates to that described 

 by Van der Stricht in the bat. 



That the interstitial cells of the ovary are physiologically active in 

 some way is attested by the fact that under certain- conditions they vary 

 greatly in number. They certainly become reduced during hibernation 

 (Cesa-Bianchi, '07) and increase during pregnancy (Regaud and Du- 

 breuil, '07-'09 ; Wallart, '07, '08; Colin," '09, etc.), and Anzilotti ('09) 

 has found that in the rabbit they undergo compensatory hypertrophy in 

 one ovary, following the extirpation of the other. In fact, many animals 

 exhibit compensatory hypertrophy, but in varying degrees, some, curiously 

 enough, being unresponsive and others remarkably sensitive. The inter- 

 stitial cells tend also to increase in number at puberty. The old idea that 

 it was possible to destroy the reproductive elements of the ovary without 

 injuring the interstitial cells is net substantiated by the recent work of 

 Regaud and Lacassague ('03). 



For the present it is well to hold an open mind regarding the possi- 



