i6 INTRODUCTION TO SEXUAL PHYSIOLOGY 



Below the pelvis the os innominatum joins with its fellow on the 

 other side at the ischio-pubic symphysis. The female pelvis 

 differs from the male in being less massive, its bones being 

 more delicate, its depth smaller, and its cavity shallower 

 and wider. 



The posterior part of the pelvic cavity is filled by muscle 

 and skin, but passages are left for the openings to the exterior 

 of the excretory and sexual organs. The anus at the end of 



Fig. 7. — Pelvis of woman ; aiitei'ior aspect. (From (iroif^^ Aiiatoiiiy.) 



the gut opens out just below (in man in front of) the sacnmi, 

 the bladder is just above (or behind) the symphysis, and the 

 sexual organs lie between them. 



The Male ()R(iAN8 



The Testicle. — In man and most of the mammals the testes 

 (or testicles) lie outside of the body cavity in a pair of pouch- 

 like sacs which together constitute the scrotum, whither they 

 descend in late embryonic life. The scrotum is suspended between 

 the anus and the urogenital opening. Each sac connuunicates 

 with the abdominal cavity by an inguinal canal through which 

 pass the spermatic cord and vas deferens or seminiferous duct. 



