The Testicle as a Gland of 

 Internal Secretion 



V. D. LESPINASSE 



CHICAGO 



The source of the internal secretion that determines the secondary 

 sexual characteristics must be, in a part at least, from the testicle. 

 In the testicle there are just three possible sources of this secretion: 

 the spermatogenic cells, the SertO'li cells, and the interstitial cells. There 

 is no question but that the source of this hormone is not in the sperma- 

 tozoa or in the spermatozoa bearing cells because in many conditions these 

 cells are destroyed and there is no change in the secondary sexual char- 

 acteristics nor in the primary sexual libido. It is not definitely proved that 

 the Sertoli cells do not produce something that is essential to the develop- 

 ment of normal sex characteristics, neither is it disproved. 



The general consensus of opinion at the present time is that the inter- 

 stitial cells of the testicle are the important cells in the production of the 

 testicular internal secretion or hormone. This is proven by the fact that 

 these cells are independent relatively of spermatogenesis. Trauma and 

 disease that destroy the spermatogenic cells do not necessarily affect the 

 interstitial cells unless quite severe and in many instances may even in- 

 crease them. This probably correlates the clinical fact that phthisis pa- 

 tients are exceptionally passionate and cryptorchitic animals always have 

 a normal sexual libido and at times the libido is greater than normal, 

 though they may have no spermatogenic tissues whatsoever. 



The Testes 



The gross structure of the testes is best seen in a sagittal longitudinal 

 section. Even a low magnification will show that the testes are 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 testes and 

 diverge in a radiate manner from the mediastinum testis. The lobules 

 are of pyramidal shapfc, 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 sections 



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