34 



suit of the methods used in fixing and staining. Some think they 

 are slightly immature types, or that the condition is produced by 

 abnormal contractions of the tail. The majority of sperms, ho^y- 

 ever, especially those from highly fertile bulls, do not show this 

 type at all. 



The most common changes in the spermatozoa, are those in 

 which there is a separation of the head from the tail, and degenera- 

 tion of the head as e^'idenced by reaction to stains. The separation 

 of the liead from the tail always occurs at the neck, and often is 

 associated with degeneration or abnormalities of the head. The 

 separation, in the majority of cases, indicates some lowering of 

 vitality in the elements, altliough in many instances traumatism 

 produced in making smears or collecting the samples is responsible. 

 Various forms of abnormal staining of the head are very common. 

 The cell membrane, wliich is normally distinct and sharp, becomes 

 blurred in outline. Normally, the head takes a good differential 

 stain, the anterior part staining lightly, and the posterior part 

 somewhat deeper. The nucleus is distinct in outline and well de- 

 fined. The lighter " inner body " stands out in well stained speci- 

 mens. As the result of degeneration, the whole head may take 

 the stain uniformly, either slightly or much deeper than normal, 

 according to the degree of degeneration. The whole problem of 

 staining, however, depends very much upon the methods used, 

 and the care with which they are applied. When a good method 

 is obtained, it should lie adhered to, and used uniformly on all 

 specimens. As a rule, however, a certain amount of practice will 

 enable one to differentiate between the sharply outlined, clearly 

 staining normal forms, and those that show abnormal reactions to 

 the stains. 



Bacteriology 



A complete bacteriological study was made of the genital tracts 

 of fourteen normal young veal calves (six to twelve weeks old), 

 four mature fertile IduIIs, and sixteen mature bulls, either sterile or 

 impotent to some degree. Together with these, the tracts of eleven 

 aborted fetuses, seven calves dying from calf infections (scours or 

 ]:)neumonia). and sixteen bulls slaughtered at an abattoir were 

 studied Ijacteriologically. Occasionally, studies were made of indi- 

 vidual seminal vesicles or testes, when these parts alone were 

 brouglit or sent in. The history of the abattoir animals was, of 

 course, quite indefinite or entirely negative. On the killing floor, 

 many tracts could be studied for pathological changes, but in the 

 bacteriological work it was difficult to care for more than two 

 tracts on each visit. 



The results of the bacteriological examinations are given in the 

 appended ta])les, in which the tracts are divided into six groups. 

 The results in Oroup I, consisting of normal veal calves, indicate 

 that the genital organs of young male calves are, under normal 

 conditions, free from bacteria. Carpenter (9) obtained like re- 

 sults in examining tlie genital tracts of heifer calves.. The cul- 



