REPRODUCTIVE ORGANS IN ANIMALS 17 



The spermatic cord contains the nerves and vessels witli which 

 the corresponding testis is su])plie(l. 



4? & ^ 





©0 a ^ jC-i-^ 



«* '^ ' -<^ 







^ 







6 



o 



U .- o 



4^ 



,^' 



-f 



Fig. 8.— Section tlii-ough testis of monkey. 



«, Seminiferous tubules ; 6, interstitial tissue ; (\ mediastinum, with small 

 tubules ; d^ vasa efferentia ; c^, vas deferens ; /, tunica albuginea. 



In the lowest group of mammals the testes remain permanently 

 in the body cavity as they do in birds and low^er vertebrates. 

 In the Insectivora {e.cj. the mole and the hedgehog) they descend 

 periodically at the commencement of rut into temporary 



