POTENTIALITIES IN FOLLICLE 



97 



phases due to either anticipation or retardation of the degen- 

 eration, rupture, luteinisation or the critical period. Any 

 disturbances in the fluid balance (cysts) and the blood 

 supply (haemorrhage), and even disturbing influences of a 

 nervous nature (shock) have an effect upon the ovo-folli- 

 cular system. From the mutual competition of these factors 

 there arises an astonishing multiplicity of formations such as 

 is not to be observed in any other combination of tissues in 

 vertebrates. 



In order to obtain a clearer insight into this multiplicity 

 we make a subdivision into the following four main groups: 



a. atresia; 



D. J^i*, \J \ W-XCH-iV^ll \,^^l.J^^H.O J. L* H_ W All. , 



c. post-ovulation corpus luteum, and 



d. -^"" 



atresia; 



pre-ovulation corpus luteum; 



post-c '"' ' ^ 



calyx. 



All these follicular descendants, moreover, have a common 

 plan of development (Fig. 70), consisting of the following 

 4 phases:— 



Fig. 70. Diagram showing the development of the follicular derivatives. 



