SECT. 197.] THE SEMEN. 433 



the spermatic cells and their mode of development, I refer to my 

 treatise in Zeitschr.f.wtss.Zoot.vii. 



Considered as a whole, as it is found in the vas deferens, the 

 semen is a whitish, viscid, odourless material, which consists 

 almost entirely of spermatozoa, with an extremely small quantity 

 of a connecting fluid between them. The chemical composition 

 of this pure semen has not yet been investigated in man ; but we 

 learn from Frerichs, that in the semen of a carp, the liquid portion 

 contains a small quantity of alkali in combination with sulphuric 

 and phosphoric acids; while the spermatozoa consist of a protein 

 substance (binoxide of protein, Frerichs), and also contain 4/05 per 

 cent, of a fat resembling butter, and 521 per cent, of phosphate 

 of lime. I myself have found in the mature semeri of the bull, 

 water, 82-06, solids, 17*94 per cent.. The latter were composed of 

 r 3* 1 3^ albuminous bodies of spermatozoa, 2*165 of phosphuretted 

 Cat, and 2*637 of salts. The emitted semen is a mixture of pure 

 semen, with secretion of the vesiculae seminales, prostate and 

 Cowper's glands. It is colourless and opalescent, has an alkaline 

 reaction, and peculiar odour. Immediately on emission, it is viscid 

 and ropy like white of egg, but on cooling it is of the consistence 

 of jelly, and after a while becomes thin and fluid. Microscopically 

 examined, the spermatozoa are seen to be contained in a consider- 

 able quantity of clear fluid, which, on the addition of water, 

 assumes the form of irregular flakes and shreds ; this undoubtedly 

 comes chiefly from the vesiculce seminales. This gelatinising sub- 

 stance, which Henle designated as fibrine, and Lehmann regards 

 as albuminate of soda, has received from Vauquelin the name of 

 spermatin. This chemist analysed human emitted semen, and 

 found six per cent, of this substance, partly in the dissolved form, 

 partly constituting the substance of the spermatozoa. The other 

 constituents were three per cent, of earthy phosphate, one per cent. 

 of soda, and the remaining ninety per cent, water. If the semen 

 be dried, the spermatozoa are usually found uninjured, the large 

 quantity of lime which they contain enabling them, it appears, to 

 resist destruction. Numerous crystals of ammouiaco-magnesian 

 phosphate are formed in the dried semen among the spermatic 

 filaments. In stains of semen, even after a long period, their 

 filaments can be recognized on the addition of a little water: thev 

 resist decomposition for a long while when kept in water, or even 

 in a putrefying animal liquid ; thus Donne saw them in putrid 

 urine which had been kept for three months. It is stated by 

 I alentin, that they even retain their form unchanged when heated 



F p 



