INTERNAL SECRETION OF OVARY 215 



large, have a well developed interstitial tissue. In these species 

 the well developed interstitial cells are present not only up to 

 puberty, but also afterwards, although the interstitial tissue is 

 much reduced when corpora lutea appear. On the other 

 hand, the interstitial tissue is rather rudimentary in the ovary 

 •of the cow, ape and man, where only one or two young are born 



Fig. 97. — L'Utear and interstitial cells (Prot, Nr. 104). x 250. Outer limit 

 of the Corp. lut. illustrated in Fig. 112. Big lutear cells; between them 

 and the theca externa consisting of connective tissue, remains of the 

 theca interna are to be seen. Then come the interstitial cells, which 

 are of smaller size than the cells of the corp. lut. — ^Prepar. of Wagner; 

 photo of Kull. 



simultaneously; in these species it hardly ever forms a 

 parenchyma hkethe interstitial tissue in the ovary of the rabbit. 

 Among Ungulata the pig is an exception, several young being 

 present in a Utter. Aschner stated that in the pig the inter- 

 stitial tissue of the ovary is much more developed before puberty 

 than in other Ungulata, although the nests of interstitial cells 

 do not form an uninterrupted parenchyma as in the rabbit. 

 Interstitial tissue in the ovary of the pig is transitional between 



