544 



E. V. COWDEY 



bility of the 4nterstitial cells forming one or more physiologically active 

 internal secretions. They may still retain, in a more or less reduced 

 degree, some of the properties of the original connective tissue cells, 



Fig. 4. Transverse section of zona vasculosa of a bat's ovary, v, vein; 1, lym- 

 phatic; and Ig, lumen formed by clumping of interstitial cells. After O. Van der 

 Stricht. 



which, according to Renant, produce internal secretions. These properties 

 may mask and modify their special activity. 



The Corpora Lutea of the Ovary 

 Anatomy 



The corpora lutea, at their stage of maximum development, are large 

 rounded masses as much as two centimeters in diameter (Fig. 5). They 

 have a yellowish color, due to a contained pigment, hence the term lutea, 

 from the Latin, luteus, yellowish. 



