Let us now consider just what is the character of this deleterious effect. From what we know of the physiology of the sexual apparatus, it must be evident that a sexual orgasm could be produced during waking hours only through strong stimulation of the activity of the testes, accompanied by liberation of spermatozoa and of the other elements of the vital fluid. Let us not forget in this connection, the statement made above: that the testis produces two forms of secretion, the internal secretion and the external secretion, the internal secretion being absorbed, produces those male characteristics which we group together under virility, while the external secretion is used for procreation. Spermatozoa do not make any part of the internal secretion. One reason for this must be evident, i.e., that being cellular elements, they could not pass through the vessel walls and be absorbed into the blood current, and if they could, by some special adaptation, get into the blood current, there is no conceivable action which they could perform in the body. We must then look upon the internal secretion as composed of the liquid elements of the testicular secretion. So far as physiologists know at present, the external secretion differs from the internal secretion only in possessing spermatozoa. When we say that the testes form their external secretion under sexual excitement only, we simply mean that they liberate or release spermatozoa under sexual excitement. The spermatozoa must be looked upon as the fertilizing element of the semen, while the liquid portion of the semen probably contains that mysterious element which, absorbed into the body, produces virility and which, passed out with the spermatozoa, may have an important role to perform in the fertilizing function.