The General Infections of the Genital Organs of Cattle 361 



the mucus removed by placing it in a 0.5 per cent, chlora- 

 zene solution for eight to ten minutes. The slide is then 

 washed with clear water, to remove all traces of chlorine, 

 and stained with carbol-fuchsin with heat for one to two 

 minutes. The carbol-fuchsin is washed off with water. 

 The film is stained for eight minutes with alkaline methy- 

 lene blue. Then the methylene blue is washed off and the 

 film is dried with filter paper. The head of the healthy cell 

 should be brought out in clear detail. The heck granule, the 

 cell membrane, and the nuclear membrane should stain very 

 dark. The nucleus should stain slightly darker than the 

 cytoplasm. If the counterstaining with methylene blue is 

 continued only about five seconds, the nucleus remains 

 bright red and the cytoplasm stains light blue, but the nu- 

 clear membrane is left indistinct. The nucleus itself retains 

 an alcoholic eosin stain better than carbol-fuchsin, but after 

 the use of eosin it is difficult to counterstain so as to bring 

 out the details. Recently, I have used acid stain consisting 

 of alcohol two parts, carbol-fuchsin two parts and eosin one 

 part. Staining is carried on one and one-half minutes, and 

 the cells then counterstained with a fifty per cent. Loeffler's 

 methylene blue for three to five seconds. By this method, 

 an exceptionally clear detail is obtained. Various stains 

 may be used, but eosin and carbol-fuchsin as acid stains and 

 Loeffler's methylene blue as a basic stain have been found 

 more satisfactory because their stability makes them- better 

 for field use than many of the aniline stains. Considerable 

 experience is required for proficiency in the proper prepa- 

 ration and interpretation of stained specimens. 



For fecundation it is necessary that a healthy sperm cell 

 unite with the ovum. Ostensibly the spermatozoon, as is 

 the case with other cells of the body, may undergo certain 

 destructive or degenerative changes affecting its physiologi- 

 cal function. This may occur during the process of sperma- 

 togenesis, in which case the immature cells are ehminated, 

 or degenerative changes may take place after the cells have 

 reached maturity and while they lie in the seminiferous tu- 

 bules or epididymis. If the sperm cell be arrested in de- 



