EXPERIMENT STATION REPORTS. 261 



agree to have a part of their herd untreated, and difficult to get them to 

 record temperatures for several days after the injections. 



"The method of treatment adopted was to cultivate the organism on 

 neutral agar until considerable growth had occurred; these were then 

 washed off with sterile salt solution, and diluted so that there wfere ap- 

 proximately 4 to 5 billion organisms per c. c. Where dead cultures 

 were used the suspension was heated to a temperature of 60 °C. for one 

 hour and transfers made to agar to determine their sterility. Where the 

 living cultures were used, they were injected within a few days from the 

 time the dilutions were made. 



"There is little in our work to encourage one in the use of dead cul- 

 tures, and there is reason to believe that injury may result in some cases 

 from the use of living cultures. Nothing but an extensive series of care- 

 fully conducted experiments will demonstrate the actions of these in- 

 jections. 



"In one herd we have recorded the following observations: Of 19 

 animals receiving living cultures at the 1st injection, 4 gave a marked 

 thermal reaction ; 11 gave a slight thermal reaction and 4 gave no ther- 

 mal reaction. 



"Of the 17 animals receiving dead cultures, 7 gave a slight thermal 

 reaction, and 10 gave no thermal reaction. 



"Of 15 animals not reacting to the test and receiving injections of liv- 

 ing cultures, 9 having calved normally only after experiencing consider- 

 able difficulty in getting them with calf; 3 have aborted; 1 has been 

 sold without learning subsequent history and 2 are sterile. Of 2 ani- 

 mals reacting to the test and one suspicious and not tested, all calved 

 normally. 



"Of 10 pregnant animals reacting to the test and receiving injections 

 of dead cultures, 4 have aborted, 4 have calved normally, and 1 died on 

 the 228th day of gestation with a normally developed calf in utero. 



"Of 6 animals not reacting to the test, and receiving dead cultures of 

 the abortus bacterium, 3 have calved normally and 3 have aborted. One 

 giving a suspicious reaction to the test, calved normally."' 



We have continued to maintain our experimental herd which was 

 available for project la and we have supervised some experimental work 

 along the line of a study of the bacterial flora of the generative organs in 

 health and disease. Mr. H. J. Stafseth, graduate assistant, and Mr. W. 

 C. Keck have undertaken this work, which will be continued. They have 

 found a similarity in flora in the vagina of healthy cattle in our herd 

 and in the uterus of cattle killed in the packing houses at Chicago and 

 Detroit. Mr. Huddleson finds abortus-like culture in the cysts of dis- 

 eased ovaries but fails to find antibodies for Bact. ahortus in the cystic 

 fluid. A further study of the cystic fluid is being undertaken since we 

 are convinced that a relation exists between ovarian degeneration and 

 infectious abortion. These men have made the serum tests on samples 

 of bovine blood. 



There have been tested during the year, 202 samples of blood (exclus- 

 ive of experimental sami)les) by the complement fixation test for infec- 

 tious abortion, of which 99 reacted and 94 failed to react, with 9 suspi- 

 cious. In one instance 14 duplicate samples were sent to another laboi- 

 atory with the ultimate results coinciding perfectly. 



