82 EXPERIMENT STATION RECORD. 



corn smut, and the presence of the species of bacteria which causes corn 

 blight, or Burrill disease. Tlie first 3 theories are of popular origin 

 and not supported by the general experience of cattle raisers. 



The results of investigations previous to those undertaken by the 

 Bureau of Animal Industry are briefly summarized, the symptoms of 

 the disease being the chief points determined by the investigators. 

 Experiments to determine the etiological importance of corn smut gave 

 negative results. A circular letter of inquiry concerning the nature, 

 distribution, and importance of the cornstalk disease was sent out in 

 1891 to a large number of farmers and cattle raisers, and the replies are 

 briefly summarized. 



The investigations detailed in this article were carried out with the 

 assistance of the experiment station at Ames, Iowa, and the methods 

 of investigation are briefly outlined. Notes are given on cattle attacked 

 and dying in 18 outbreaks in different portions of the State, and the 

 symptoms of the diseased animals and the results of post-mortem 

 examinations are detailed. 



To determine the connection of cornstalks affected with corn blight, 

 or the Burrill disease, with the cornstalk disease, diseased cornstalks 

 were fed exckisively to cattle which were carefelly watched for several 

 weeks, but no evidence of disease appeared. Eight rabbits, fed upon 

 cornstalks and leaves known to be infected with the bacillus of the 

 Burrill disease, became emaciated, but only 2 died. The bacillus of 

 the Burrill disease of corn is thus regarded as possessing an innocuous 

 nature. Tlie bacillus was isolated and pure cultures made. It was 

 identified as Bacillus cloacm. It occurs in the soil and in the stalks 

 afl'ected with corn blight. 



Although previous experiments to test the effect of feeding corn 

 smut to animals had given negative results, further experiments were 

 made, cattle being fed almost exclusively on smut-laden cornstalks and 

 free smut for several days. The animals continued perfectly well 

 throughout the time of feeding and for several months afterwards, 

 during which they were kept under close observation. A table is 

 given showing the daily temperature of the animals daring the feeding 

 experiment. 



Instances of cattle and sheep dying while pasturing in cornstalk 

 fields were reported to the investigators, but there was no evidence of 

 the existence of the cornstalk disease in horses, sheep, or swine. Corn- 

 stalks, leaves, tassels, and the liver of a steer dying from cornstalk 

 disease were subjected to a careful chemical analysis without the pres- 

 ence of any alkaloidal poison or unusual quantities of inorganic salts 

 being revealed. 



A discussion of the nature of the disease, based upon data obtained 

 in the special investigation, is given, and the conditions under which 

 the disease occurred are elaborated in an extensive table. In general 

 the symptoms were those of mviscular weakness, merging into paralysis, 



