CHANGES IN THE OVARY 139 



Sobotta describes the outer theca as takiiig no share in the ingrowth, 

 while the theca interna is stated to become entirely spent in the 

 formation of the inter-epithelial anastomosis. The hypertrophy of 

 the epithelial cells is said to be of the nature of a simple enlargement, 

 unaccompanied by division. 



Sobotta's conclusions in regard to the development of the corpus 

 luteum in the mouse were subsequently confirmed by him in a further 

 investigation carried out on similar lines on the corpus luteum in the 

 rabbit.^ Moreover, Stratz ^ published descriptions of certain stages 

 of corpus luteum formation in Tarsius, Tupaia, and So7-ex, and these 

 agree in essential particulars with those given by Sobotta; while 

 Honore,^ also working on the rabbit, differed only in concluding that 



Fig. 39. — Early stage in formation of corpus luteum of mouse. 

 (From Sobotta.) 



I, Developing luteal cells ; e, germinal epithelium. 



the inter-epithelial network is derived in part from the theca externa, 

 and not exclusively from the theca interna, and that the latter is not 

 entirely exhausted by the ingrowth, some part of it still remaining 

 to form a layer within the outer theca in the fully formed corpus 

 luteum. 



On the other hand, several investigators have expressed doubts 

 regarding Sobotta's conclusions, and some have adopted the theory 

 originally formulated by von Baer that the luteal cells arise from the 

 connective tissue sheath of the follicle, the follicular epithelium being 

 either entirely discharged along with the ovum or else being partially 



' Sobotta, " tjber die Bildung des Corpus Luteum beim Kaninchen," Anat. 

 Hefte, vol. viii., 1897. 



2 Stratz, Der Oesohlechtsi-dfe Saugethiereierstock, Haag, 1898. 



^ Honor6, "Eecherches sur I'Ovaire du Lapin," Arch, de Biol., vol. xvi., 

 1900. 



