AMERICAN FOULBROOD. 17 



toneally and one intravenously. The temperature taken of the latter 

 two tlu'oughout the day of the inoculation was found to be increased 

 about 3° F. following the inoculation. The next day they were 

 somewhat sluggish with impaired appetite. The temperature, how- 

 ever, soon declined to normal and their feechng became normal. 

 The 1,500 gram rabbits were from 100 to 200 grams light in weight 

 on the day after the inoculation but soon the loss was regained. 

 Observations were made over a period of 2 montLs. Autopsies on 

 the chloroformed animals showed ho abnormalities worthy of note. 



Four guinea pigs inoculated subcutaneously with cultures similar 

 to those used in the rabbit inoculations showed only slight reaction. 

 The temperature of the one taken throughout the day of inoculation 

 showed a rise of about 2° F. but was normal thereafter. No loss in 

 the weight of these 400 to 500 gram guinea pigs was appreciable. 

 One died in 10 days, apparently from causes foreign to the inocu- 

 lation. The remaining three were chloroformed after 6 weeks and 

 presented no abnormalities of jiote at autopsy. 



Two gray rats were inoculated subcutaneously, one with the vege- 

 tative and the other with the spore form of Bacillus larvae. These 

 proved to be refractory. After 4 weeks they were chloroformed and 

 at autopsy no abnormality of interest was noted except a sUght 

 infiltration at the point of inoculation in the animal receiving the 

 vegetative culture, and a small abscess in the case of the animal 

 receiving the spore suspension. In the abscess spores were present. 



TECHNIQUE 



Much of the time devoted to the study of American foulbrood has 

 been consumed in the study of technique. Special media were re- 

 quired and the method of conducting the experimental studies had 

 to be developed. 



MEDIA 



Failure to recognize the fact that the spores occurring in such large 

 numbers in the brood dead of American foulbrood do not grow on 

 the media ordinarily used in the laboratory has caused a number of 

 workers to go astray and has contributed not a little to the confusion 

 that has existed concerning the brood diseases. Lambotte (13) in 

 Belgium experienced some difficulty in obtaining cultures following 

 inoculations with the spore-bearing disease material. He made a 

 medium using the brood of bees in its preparation and with it obtained 

 a growth which he interpreted as being the species represented by 

 the numerous spores present in the brood dead of the disease. The 

 interpretation was evidently incorrect. The cultiu-e which he ob- 

 tained he identified as a member of the mesentericus group. In 1903, 

 before learning of Lambotte's work, the writer ( 20) had made an agar 

 using bee larvse and obtained a germination of the spores of the 

 132862°— 19— Bull. 809 2 



