EXPERIMENT STATION BULLETINS. 413 



This treatment produced no apparent results. 



Dark calved normally, April 10, 1912. 



Light calved normally, April 15, 1912. 



No deductions can be drawn from this experiment except it be that 

 injections of living- abortion bacilli, unless more virulent than the strain 

 employed by us, may be made either intravenously or subcutaneously 

 with impunity on caitle either ])regnant or non-pregnant. It was hoped 

 and expected that Dark would abort thus showing the i)athogenie, aborti- 

 facient properties of the organism used and that Light would not abort 

 showing an artificial immunity due to the original subcutaneous injec- 

 tions or, if abortion took jjlace, showing the inadequacy of such injec- 

 tions. The organism must be greatly attenuated. 



The effect of injections of dead cultures or of the products of the 

 growth of abortion germs may be further seen in the following experi- 

 ments conducted with a view to test the efficacy of "abortin" as a 

 diagnostic agent. 



"Abortin" was first described by M'Fadyean and Stockman^ who 

 recognized in it only limited possibilities. BriilF reports unfavorably 

 on its use. Our results are reported because they indicate that a reaction 

 takes place in some cases. We cannot come to a conclusion as to the 

 value of this test even after studying our results. The test should be 

 studied a number of years longer to thoroughly test its worth and possi- 

 bilities. The injection of "abortin" may have some immunizing effects 

 available in preventing an infected animal from aborting. Some of our 

 records indicate this possibility very strongly. This is more significant 

 in view of the fact that many abortions had taken place up to the time 

 of the application of the tests recorded in Table II when all the pregnant 

 animals in the herd were tested. No abortions took place after this 

 test was made, although in one case at least (Molly B) there were sus- 

 picious symptoms of abortion between the time of the test and the date 

 of normal calving. It is possible that 21A and llAl were also favorably 

 affected by the treatment. 



The "abortin" which we used was made by growing Bact. abortus 

 (Goda and MacNeal) in naturally sterile horse serum 10 c.c. -|- gly- 

 cerinated bouillon 60 c.c. for 49 days at 37°C. Cloudiness was con- 

 siderable and sediment abundant. The cultures were heated for 30 

 minutes in steam and filtered several times through filter ]>aper. conse- 

 quently contained many dead organisms. The material was preserved 

 in .5 per cent phenol by addition of one part to nine of 5 per cent solu- 

 tion of phenol. The "abortin" used by us is designated ''E" made from 

 pure culture of "MacNeal" and "B" and "C" made from culture "Goda." 

 It is not at all improbable that a more powerful reagent can be made 

 capable of giving better results. 



Certainly, nothing definite can be concluded from the data recorded 

 here. A study of Table III may throw some light on the value of 

 "abortin" as a diagnostic ngent. The first column contains the names 

 of the cows that did not react to the test and calved nonnally. It is 

 ])resumed* that these animals were not affected with the abortion g-erm. 

 In the second column are the names of those that reacted, yet calved 

 normally. It is \'ery probable that these animals were affected with the 

 abortion germ yet carried their foetuses to full term as not infrequently 

 happens. They may have been protected by the dose of "abortin" against 



