ANATOMICAL FEATURES 



RECTUM 



URINARY BLADDER 



AMPULLARY PORTION 

 OF VAS DEFERENS 



SEMINAL VESICLE 



EJACULATORY DUCT 



PUBIC BONE 



PROS TATE GLAND 



VAS DEFERENS 



SPERMATIC BLOOD 

 AND LYMPH VESSELS 



EPIDIDYMIS 

 TESTIS 



INGUINAL BURSA 

 SCROTUM 



Fig. 2. Sketch of male reproductive system in man. 



breeding season, as in the bat, Myotis, where the testes pass into a temporary 

 perineal pouch or outpushing of the posterior abdominal wall during the 

 reproductive season, to be withdrawn again together with the scrotal wall 

 when the breeding period is past (fig. 4D). A similar periodic behavior is 

 true of many insectivores, such as the common shrews, the moles, and the 

 European hedgehog (Marshall, '11). 



The permanent scrotum is a pendent structure, in some species more so 

 than others. In the bull and ram, it extends from the body for a considerable 

 distance, whereas in the cat, hippopotamus, tapir, guinea pig, etc., it is closely 

 applied to the integumentary wall. In primates, including man, in most carni- 

 vores, and many marsupials, the pendency of the scrotum is intermediate 

 between the extremes mentioned above. 



An exceptional anatomical position of the testes in the lower vertebrates 

 is found in the flatfishes, such as the sole and flounder, where they lie in a 

 caudal outpouching of the peritoneal cavity (fig. 5). The testis on either side 

 may even lie within a special compartment in the tail. (The ovaries assume 

 the latter position in the female.) 



