138 



THE TESTES, BY V. LA VALETTE ST. GEORGE. 



Henle* has very carefully examined these interstitial columns 

 of cells, and has sketched the appearances presented. He 

 states that they consist of a finely granular substance, not 

 unlike the contents of the ganglion cells, that includes nuclei 

 which from their uniform and small (3 ft) size, spheroidal form, 

 and the generally apparent central nucleolus, can be readily 

 distinguished from the variable nuclei of the cells lining the 

 tubuli uriniferi. Henle regards it as an essential constituent 

 of the gland, though unable to assign to it any functional 

 value. From this recapitulation of the different views that 

 have been held, it is easy to see that the determination of the 

 nature and function of these cell heaps remains enigmatical. 



After the seminiferous tubules have entered the mediastinum 

 testis, they lose their proper wall, and become continuous with 

 the more or less dilated and irregular canals of the rete 

 testis. 



The vasa efferentia are thicker than the afferent tubes, being 

 from 0'6 to 0'4 of a millimeter in diameter, and possess a 

 special layer of smooth muscular fibres in their investment. 



CELL CONTENTS OF THE SEMINIFEROUS TUBULES. The 

 contents of the tubules consist of cells, the external layer of 



Fig. 170. 



Fig. 170. Cells of the outer layer of the tubuli seminiferi. a, 6, 

 from the Bull ; c, from the Dog. 



which has been termed their epithelium. Though I cannc 

 admit the correctness of this nomenclature, I am neverthel< 

 able to demonstrate that the cells constituting this periphei 



* Handbuch der Eingeweidelehre, p. 358. 



