358 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



tion of the grain while in shocks in the fields. Again, reports have 

 coine from eastern Oregon, in a vast wheat-growing section, of a like 

 disease alTecting the horses except that it is of a much more chronic 

 type. The nature of this disease is evidently very closely allied to 

 that found in the corn-growing States, as brain tissues from affected 

 horses in Virginia and Oregon showed practically the same macro- 

 scopic and microscopic appearances. 



Since tlie close of the fiscal year covered by this report the disease 

 has appeared extensively in Kansas, Nebraska, and adjoining States, 

 but it has now subsided. The bureau rendered assistance by sending 

 20 veterinarians to investigate the disease and advise the farmers. 



On account of the possibility of the identity of the disease in this 

 country with the Borna disease of Germany, an endeavor was made 

 to demonstrate the presence in this disease of the so-called intranu- 

 clear bodies lately described by Joest, of Germany, but these could 

 not be found. 



A significant fact in the bacteriological study of several brains 

 showing well-defined lesions has been the isolation of microorganisms 

 which bear a remarkable similarity both morphologically and cul- 

 turally to the diplococcus described by Johne as being present in 

 the Borna disease. But the organism with which we have dealt has 

 never shown any tendency to grow in chains as do the streptococci 

 isolated by Ostertag, and therefore the resemblance is closer to the 

 coccus described by Siedamgrotzky and Schlegel as being the cause of 

 the Borna disease, which these authors claim is a serious cerebro- 

 spinal meningitis. In the cases so far examined bacteriqlogically the 

 diplococci have usually been found accompanied by some other bac- 

 teria, but the diplococci, although very few in number, have always 

 been the preponderant organism. 



Pathogenic properties have not been shown by inoculations made 

 on experiment animals. It is possible that all of these organisms 

 repiresent an agonal invasion from the intestines and have no causal 

 connection with the disease. In connection with the coccoid organ- 

 isms it may be noted that from the number of affections of the horse 

 produced by them this animal appears to be peculiarly susceptible 

 to their action. 



On account of the very old and very plausible theory so often 

 advanced that the disease is due to toxic substances existing in 

 damaged grain and fodder, a number of species of fungi were 

 isolated from damaged corn and grown on a sterilized corn medium 

 in an effort to produce some toxic substance that would create disease 

 when fed to horses. The fungus in pure culture was allowed to grow, 

 for periods of about one-month's duration, in flasks containing 250 

 c. c. of the nutrient medium, and the contents of a flask were fed 

 each day for a period of 30 days along with a sufficient quantity of 

 sound corn and hay to make a normal ration, but no symptoms 

 developed in the experiment animals. 



It is possible that laboratory conditions alone can not be made to 

 parallel sufficiently closely those which exist naturally in the growing 

 ])lants, and that toxic substances which might be produced in a 

 natural state could not be generated in a corn-meal medium in the 

 laboratory. The by-products of the growth of both fungus and 

 bacteria on corn and fodder should certainly receive more considera- 

 tion in future work. To conduct an ideal experiment along this line 



