43 



appearance until at the twentieth service, when the fluid is thin 

 and watery," It seemed as though there was a well marked reduc- 

 tion in the number of spermatozoa per cubic centimeter in the ad- 

 vanced servdces. Successive copulations also resulted in a marked 

 decrease in the number of motile spermatozoa, together with a 

 sliorter duration of perceptible vitality. The certainty of produc- 

 ing impregnation at the same time became less and less. "This 

 reduction in the per cent of effective matings when the male is 

 sexually overworked is recognized hy those engaged in animal 

 breeding as one of the most noticeable and universal concomitants 

 of heavy sexual service." 



In another paper, these same authors studied the effect of sexual 

 excess upon the character of the offspring. In part, they conclude : 

 ''Ba' no means thus far used has any inferiority of i)rogeny from 

 the heavy sexual service been discovered. They are fully equal if 

 not superior to progeny from very light service of male." 



Infection is without doubt the greatest single factor capable of 

 producing functional and anatomic changes resulting in varying 

 degrees of imi)oteiicy and sterility. The changes produced range 

 from the addition of the toxic products of bacterial growth to the 

 seminal fluid, to the complete destruction of the parenchymatous 

 tissue of one or more of the contributing sextial glands. Anatomic 

 changes are l)y no means essential to the ])roduction of lowered 

 fertility. As has been previously stated, the work on veal calves 

 indicates that the genital organs of young bulls are normally free 

 from bacteria. Likewise in normal adult animals, the bacterial 

 content of the genital organs is as a rule low or negative. It is 

 possil)le that a certain flora is normal for the tract at sexual 

 maturity, as in several other organs of the body, but under the 

 strain of sexual excess, defective diet, or other weakening in- 

 fluences, the5-e organisms may become pathogenic. Streptococci and 

 staphylococci have at times been found in apparently normal parts 

 of the body, and at other times they are found associated with 

 severe pathological lesions in the genital tract. The degree of 

 pathogenicity is of course difficult to determine, except as we find 

 the bacteria associated with abnormal conditions. Carpenter (9), 

 however, injected streptococci into the genital tracts of female 

 calves and produced lesions resem])ling very closely those from 

 which the organisms had been isolated in adult sterile animals. Per- 

 sonally. I am inclined to believe that the genital organs normally 

 are free from bacteria, or if any are there they are better able 

 to multiply under the strain of devitalization of the tis.sues. 

 Bacterial invasion, liOAvever, does take ]ilace fpiito fi-equently. l)ut 

 the paths of entrance of the organisms are .somewhat proble- 

 matical. Hematogenous origin is always possible, though it is 

 rather difficult to definitely implicate this mode of entrance. The 

 urethra is perhaps the easiest and most common ]iath for the 

 entrance of bacteria, though even here it is not ])Ossible to make 

 definite assertions. Contiguous spread of infection from neigh- 



