342 ELEMENTARY PHYSIOLOGY. [XXXII. 



c. The bands and lamellae of fine connective 

 tissue running from the septa between the 

 tubuli seminiferi. 



d. Polyhedral granular cells scattered about in 

 the tissue between the tubuli seminiferi. 

 These are very numerous in some animals, 

 and to see them in number, a section of the 

 lobular part of the testis of a pig should 

 be cut. 



e. The tubuli seminiferi. In these note 



a. The membrana propria; in some animals 

 this is thick and is formed of several 

 layers of flattened cells. 



/3. Tubes lined by cells lying three or four 

 deep and arranged as an inner single 

 layer of short columnar and flattened 

 polyhedral cells, and an outer layer of 

 less regular cells two to three deep. 

 Amongst the cells much larger ones 

 may sometimes be seen. 



7. Tubes like the above but with the out- 

 lines of the cells bordering the lumen 

 less distinct and with bundles of sper- 

 matozoa imbedded amongst them. In 

 different tubes the spermatozoa are in 

 different stages of development; in all 

 cases their heads (more deeply stained) 

 are in the peripheral parts of the tubes 

 and their tails directed to the lumen. 





