WITHIN MALE REPRODUCTIVE STRUCTURES 



179 



-OVARIAN FOLLICLE 



(CERTAIN TELEOST 



SUCH AS GAMBUSIA, 



PERITONEAL CAVIT 



(CERTAIN URODELES) 



(OCCASIONALLY IN 



BIRDS) 



ANTERIOR OVIDUC 



(MAMMALS, SHA 



BIRDS, REPT 



POSTE 



a 



(URO 

 (G YMN 

 (CERT 



\ EXTERNAL 



(MOST FISH 

 MOST A N U R Al 



Fig. 98. Sites of normal fertilization (x) in the vertebrate group, 

 below mammals. (B) Mammalia. 



(A, C) Vertebrates 



upon a lingering passage of the sperm through the epididymal portion of the 

 male genital tract. 



a. Possible Factors Involved in the Passage of the Seminal Fluid from 

 the Testis to the Main Reproductive Duct 



1) Accumulated Pressure Within the Seminiferous Tubules. The oozing 

 of sperm and seminal fluid from the seminiferous tubules through the rete 

 tubules into the efferent ductules of the epididymis possibly may be the result 

 of accumulated pressure within the seminiferous tubules themselves. This 

 pressure may arise from secretions of the Sertoli cells, the infiltration of fluids 

 from the interstitial areas between the seminiferous tubules, and by the addi- 



