SEMEN Masculinum, in the animal economy, is a white, liquid matter or humour, the thickest of any in the body, separated from the blood in the testicles, and reserved in proper vessels, to be the means of generation. By chemical analysis it is found to consist almost entirely of oil and volatile salts blended together by the mediation of a little phlegm. See ANIMALCULE, n° 48 et seq.