126 GEORGE W. CORNER 



those of Rabl, and he thinks the layer of theca cells is not des- 

 tined to persist, but is a 'matrix' or source of origin for the newly 

 forming connective tissue of the corpus luteum. 



With this group should be placed one of the most ambitious 

 of the recent attempts to work out the origin of the human corpus 

 luteum, that of R. Meyer ('11 a). The paper describes five 

 corpora lutea in process of formation, of which one is claimed by 

 the author to be the youngest ever obtained in the human. The 

 appearance of the structures and the menstrual histories were 

 the only guides to their age. The specimens show first a prolif- 

 erative stage, during which the granulosa cells swell and acquire 

 granules of a fatty substance, and, second, a stage of 'glandular 

 metamorphosis' through vascularization of the granulosa layer. 

 The first spindle-cells seen in the lutein layer arise from the blood- 

 vessels, which are sprouting inward. The wall is thrown into 

 folds, in which the larger fat-infiltrated theca interna cells are 

 crowded. Here they remain until the pressure of the swelling 

 lutein tissue crushes them out of existence, an event which may 

 be early or late according to the internal conditions of pressure. 

 Groups of them, serving as sources of nutrition for the growing 

 organ, may be seen about the periphery of the corpus luteum 

 and in the folds of its wall, until fairly late in the life of the corpus 

 luteum. The name theca-lutein cells has been given them. 



As an example of the difficulty of proving anything about the 

 origin of the corpus luteum by specimens 'whose age can only be 

 guessed, it may be mentioned that the genuineness of Meyer's 

 first and supposedly youngest corpus luteum has been sharply 

 attacked. Ricker and Dahlmann ('12) have hinted that it is not 

 even a naturally ruptured follicle, and J. W. Miller ('11) believed 

 it was an atretic follicle, because Meyer had stated the granulosa 

 cells to contain 'Fett,' while, according to Miller, neutral fat is 

 never found in the normal fresh corpus luteum. It must be ad- 

 mitted that this criticism was rescinded when Meyer ('lib) stated 

 that 'Fett' meant merely lipoids in general, and that Miller is 

 himself no opponent of Meyer's views. But after all we shall 

 never be certain of the early human corpus luteum until skill and 

 good fortune enable someone to obtain the tubal ovum with the 

 ovary. 



