THE SEXUAL ORGANS. 227 



filaments may always be found in the nuclei, in the internal 

 portions of the gland, and frequently in every seminiferous 

 tube without exception. But in the normal course of things 

 the spermatic filaments in the testis itself do not become 

 liberated at all, or in very small proportion, and the tubuli 

 seminiferi, consequently, are by no means the situation in 

 which spermatic filaments are to be sought for, although even 

 here, on the addition of water, which causes the substance 

 by which they are enclosed to burst, they will always be 

 found. They do not occur in the free state before reaching 

 the rete testis and coni vasculosis First, the nuclei burst, 

 and the filaments remain in the spermatic cells, in which, when 

 numerous (10 — 20), they are very regularly disposed in close 

 apposition, with the heads and tails together, in a curved 

 bundle, or when in less number, confusedly aggregated. Ulti- 

 mately these cells and cysts also burst, the filaments are libe- 

 rated, and, forming a dense entangled crowd, entirely fill the 

 epididymis, still in part associated in bundles, which, how- 

 ever, also are soon broken up, in part isolated. In the lower 

 portion of the epididymis, the entire process of development 

 is usually concluded, though it happens, not unfrequently, that 

 isolated transitional forms are conveyed still farther, and are 

 not completely developed before reaching the vas deferens. 



The semen, regarded as a whole, as it is found in the vas 

 deferens, is a whitish, viscid, inodorous material, consisting 

 almost entirely of spermatic filaments, and containing between 

 those bodies an extremely minute quantity of a connective 

 fluid. The chemical composition of this unmixed semen has not 

 yet been investigated in Man ; but we know through Frerichs, 

 with regard to the semen of the Carp, that the spermatic fluid 

 contains no albumen, some little mucus, and, of salts, chloride of 

 sodium, and a small quantity of alkaline sulphates and phos- 

 phates ; whilst the spermatozoa consist of a protein compound 

 (according to Frerichs, binoxide of protein), and contain 

 besides 4*05g of a yellowish, butyraceous fat, and 5*21g of 

 phosphate of lime. The semen, as ejaculated, is a mixture of 

 pure semen and of the secretions of the vesiculce seminales, 

 the prostate and Cowper^s glands. It is, in this condition, 

 colourless, opalescent, with an alkaline reaction and peculiar 

 odour; when emitted, it is viscid and glutinous, like albumen, 

 but on cooling becomes gelatinous, and after some time again 



