12 INTERNAL SECRETIONS OF THE OVARY 



products of follicular atresia and luteal degeneration. Their 

 origin is variously ascribed to three different sources : 



(a) Direct derivation from the germinal epithelium; Paladino 



(483), Lane-Claypon (340) and others. 



(b) Derivation from the follicle, either from old corpora 



lutea, atretic follicles or theca interna; Schron (550) 

 and Rabl (522). 



(c) Derivation from transformed connective tissue cells ; 



Sainmont (540), Regaud and Policard (527) and 

 Athias (47). 



Others again, as Van der Stricht (603), consider a combination 

 of one or more of these sources to be probable. Criticisms of all 

 these views are obvious and further discussion is unwarranted 

 here. 



The interstitial tissue has been said to show cyclic changes 

 during the oestrous cycle (O'Donoghue, 480, Lane-Claypon, 340), 

 but owing to the present doubt as to whether it is an essential 

 constituent of the mammalian ovary, and to the uncertainty of 

 its origin, it is difficult at the moment to assign to it any definite 

 physiological role. According to Steinach (590), Lipschiitz 

 (366) and others, it is the main endocrine tissue of the ovary and 

 constitutes the ' puberty gland ' of these authors. 



Accessory ovarian tissue. Ovarian tissue apart from the two 

 main ovaries may occur in rare instances, according to Waldeyer 

 (628), Beigel (55), Wilhams (638), Hartman (276) and other 

 workers. In the dissection of some thousands of mice, however, 

 the writer has found only two with accessory ovaries, and in 

 each case the abnormality consisted of a supplementary body 

 within the same capsule as the normal ovary. The problem 

 of third or accessory ovaries is of physiological importance as 

 it may complicate the operation of complete ovariectomy 

 (see p. 98). 



{h) THE ACCESSORY REPRODUCTIVE ORGANS 



In mammals the accessory female reproductive organs are 

 designed for the fertilization of the ovum, the gestation of the 

 embryo, and the subsequent suckling of the young. To this end 



