THE MALE GENITAL ORGANS. 



363 



posterior portion to form the mediastinum testis, or the corpus 

 Highmori, which projects as a fibrous-tissue ridge for a variable 

 distance into the substance of the testis. The gross structure of the 

 testis is best seen in a sagittal longitudinal section. Even a low 

 magnification will show that the testis is composed of lobules. These 

 are produced by septa which extend into the substance of the organ 

 and are derived from the investing tunics of the testis and diverge in 

 a radiate manner from the mediastinum testis. The lobules are of 

 pyramidal shape, with their bases directed toward the capsule and 

 their apices toward the mediastinum. They consist principally of 

 the seminiferous tubules, whose transverse, oblique, and longitudinal 



Lobule of testis. Tunica albuginea. 



_Caput epidi- 

 dymiais. 



' Corpus Highmori 

 ~~~ and rete testis. 



Blood-vessel . 



Tubuli recti. 



- Vas epididymidis. 



Fig. 290. Longitudinal section through human testis and epididymis. The light areas 

 between the lobules are the fibrous- tissue septa of the testis ; X 2 > 



sections may be observed in sections of the testis. When isolated, 

 these tubules are seen to begin in the testis as closed canals, which 

 are closely coiled upon each other (convoluted tubules) and describe 

 a tortuous course, until they finally reach the corpus Highmori. 

 Immediately before they reach the latter, the convoluted tubules 

 change into short, straight and narrow segments the straight 

 tubules, or tubuli recti. Within the corpus Highmori, all the straight 

 tubules of the testis unite to form a tubular network the rete testis 

 (Haller). 



From this network about fifteen tubules the vasa efferentia 



