HISTOLOGY 



135 



The spermatozoon is composed of the head, the middle piece and the 

 tail or fiagellum. The head is flattened and hook-shaped, and ranges from 

 .0068-.0102 mm. in length with a mean length of .0081 mm. The total 

 length ranges from .1190-.1265 mm. with a mean length of .1227 mm. 

 (Figures are based on 30 measurements made by Margaret Nickson.) 



Fatbody^ 



'Caput epididymidis 



Ductuli efferentes- 



x -\ 



-•5, 



Corpus epididymidis 



J — Ductus deferens 



Testis 



"Cauda epididymidis 



Fig. 64. — Drawing of the testis, efferent ducts, epididymis and ductus deferens. ( X6.) 



It was mentioned previously that the intertubular tissue contains small 

 groups or cords of interstitial cells of Ley dig. These cells have large round 

 nuclei which contain one, or more often two, nucleoli and rather coarse 

 chromatin granules. The cytoplasm stains intensely with eosin. 



The excretory ducts of the testis include the rete testis, the efferent 

 ducts, the epididymis w^hich has three parts, the caput, corpus and cauda, 

 and the ductus deferens (Fig. 64). 



At the hilus the seminiferous tubules are collected into the network of an 

 anastomosing system of canals, the rete testis, which is lined by simple, low 

 cuboidal or at some places flattened epithelium. The network opens into a 

 single lacuna which, outside the tunica albuginea, branches into as many 

 parts as the number of efferent ducts. According to Benoit (6) this number 



