The General Infections of the Genital Organs of Cattle 359 



proportion of bulls as of cows go to slaughter on account of 

 sterility or low fertility. 



A general outline for the clinical examination of the geni- 

 tal organs and the semen of bulls has been given in Chapter 

 II. It remains to describe more fully the examination of 

 the semen in the course of genital diseases and to point out 

 as far as possible the relation of changes in the semen, and 

 especially in the spermatozoa, to clinical manifestations of 

 genital disease. 



^The technique which I have pursued in collecting and 

 examining semen from bulls is as follows : 



The bull's sheath is first douched with I/2 Per cent. Lugol's 

 solution or i/^ per cent, chlorazene. The cow's buttocks are 

 thoroughly cleansed with a disinfectant and washed with a 

 y-2 per cent, chlorazene solution, and the vaginal mucus is 

 removed manually. If a bacteriological examination of the 

 semen is desired, the vagina should be thoroughly cleansed 

 with a douche of 14 per cent, chlorazene, which must be com- 

 pletely removed several minutes before copulation. As only 

 a slight trace of chlorine or other disinfectant will cause im- 

 mobility of the sperm cell, it is desirable that cleansing of 

 the parts for studying the motility of the spermatozoa be 

 done with sterile water or a normal saline solution. In 

 either case, all possible vaginal mucus should be removed, 

 just prior to service, with the well disinfected hand which 

 has been washed with sterile water. The method is not en- 

 tirely satisfactory from the bacteriological standpoint. Two 

 sources of bacterial contamination must be considered: 

 first, extraneous, and second, the vaginal flora. Contamina- 

 tion from the first source may be largely prevented by care- 

 fully cleansing the parts immediately prior to inserting the 

 hand for the sample, but, owing to the almost constant fecal 

 contamination of the vulva and the adjacent parts, it is well- 

 nigh impossible wholly to prevent contamination during 



1 The results of clinical examinations of bulls, with ditections for the ex- 

 amination of semen and spermatozoa from diseased or suspected bulls, are 

 by W. W. Williams ; the micro-photographs of the preparations are by 

 Professor B. F. Kingsbury. 



