BUREAU OF ANIMAL INDUSTRY. 357 



Some strains would kill white mice with septicemia within 48 hours, 

 when others failed to do so, but would produce necrotic areas in the 

 liver and spleen within two and one-half months, while still others 

 would fail to produce any lesions at all in these animals. The ditfer- 

 enee in pathogenicity was not alone noticed in different strains of 

 Bacillus abortus in these and other anim.als, but also in the same 

 strain but of a different generation, the organism losing its pathoge- 

 nicity with life on artificial media. Kittens and dogs are still under 

 observation, the first batch of kittens used dying within three weeks 

 with enlarged and hemorrhagic spleens and waxy livers, but in 

 these cases the organism has not as yet been recovered. Chickens have 

 only in one instance shown small necrotic foci and petechial s^jots in 

 the liver as a result of feeding cultures of Bacillus ahortu-s. 



Continued efforts Avere directed toward obtaining a biologic product 

 which would prevent abortion in already pregnant animals and also 

 in animals about to be bred. Observations up to date do not warrant 

 the drawing of any definite conclusions. Over 250 head of cattle have 

 been thus treated three or four times, and only a very small portion 

 of this number have as yet calved. In a small herd treated early in 

 this work the results were not encouraging, but failure in those cases 

 may be attributed to the facts that a very thin su'^pension of bacterin 

 had been injected, and, secondly, just one strain had been used in the 

 preparation of the bacterins. Since the different strains have been 

 found to vary somewhat, subsequent experiments have been conducted 

 with denser suspensions made from a number of our most virulent 

 strains, and the preliminary results thus far obtained with these in- 

 jected cattle have been more satisfactory. For a more definite decision 

 on the value of this line of vaccination the results of the treatment of 

 the latter animals must be awaited. 



Besides the above-mentioned work the diagnosis of the disease by 

 the complement-fixation and agglutination tests has been successfully 

 carried out on over 400 cases with satisfactory results. Studies are 

 also being conducted with reference to the immunizing effect which 

 infected milk from a " bacillus-carrier " mother will have upon the 

 calf when it becomes adult. 



FORAGE POISONING OR CEREBROSPINAL MENINGITIS. 



The etiology of the disease variously known as forage poisoning, 

 cerebrospinal meningitis, stagirers, etc, being yet of such an obscure 

 and puzzling nature, an attempt was made to learn more of a practical 

 character in connection with the disease when occasion permitted. As 

 it is such a very serious and fatal malady, the solution of the various 

 questions connected with it is extremely important. 



From numerous letters received during the months from November 

 until July relative to the death of horses and cattle from eating moldy 

 corn and fodder it is apparent that forage poisoning exacted a heavy 

 toll during the past year. These letters were received from Pennsyl- 

 vania, Maryland, Virginia, AV'est Virginia, Kentucky, Missouri, Kan- 

 sas, and south into Oklahoma. In fact, letters of inquiry were occa- 

 sionally received from throughout all of the corn States The present 

 year has seemed to be an especially bad year all through that section 

 on account of the very dry summer being followed by a wet, warm 

 fall, which is conducive to the development of molds and fermenta- 



