8 INTERNAL SECRETIONS OF THE OVARY 



mitotic proliferation. Doubt still exists as to the degree to 

 which the various follicular elements are concerned in the 

 transformation. 



Von Baer (53) originally described the corpus luteum as 

 originating solely from the theca interna, and one or two 

 comparatively recent writers have adopted this view. It is 

 now generally admitted, however, that the remains of the 



ii.— 



Fig. 3. — Part of Corpus Luteum of Pregnancy 

 OF Mouse. 



l.g. lutein granule; n. nucleus. 



follicular epithelium play the major part in the formation of the 

 true lutein cells, and the real problem relates to the part played 

 by the theca interna. According to Sobotta for the mouse 

 (583-6) and guinea-pig (587), Van der Stricht for the bat (601-3), 

 and Marshall for the sheep (440, 442), the lutein cells are derived 

 exclusively from the follicular epithelium, the theca interna 

 merely assisting in supplying the vascular connective tissue 

 framework for the corpus luteum. 



In other species, however, the theca interna has been described 

 as undergoing a burst of growth at the time of ovulation, and 



