VASCULAR SINUSES. 81 



another. Such sinuses may be interposed between the terminal 

 arteries and the commencing veins, taking the place of capil- 

 laries, as in the spleen and bone-marrow. 



The erectile tissue of the male and female genitals consists 

 of similar vascular sinuses so arranged that when the exit of 

 the blood is checked by muscular compression of the outlet- 

 veins the spaces are distended with blood and the organ be- 

 comes turgid and erect. 



6- Hist. 



