68 > HISTORICAL NOTES ON BEE DISEASES. 



quently seen in cultures from the throat. Now, it may be that Wilson 

 made a correct identification, but inasmuch as the source of the 

 culture was the throat, he should have been very careful about 

 making the identification positive. 



It might be mentioned here that not a few bee keepers have been 

 startled by an announcement that B. alvei is found in human sputa. 

 Some of them have reasoned, very naturally, that if all reports were 

 true the sputum might be the source of foul-brood infection, but 

 there is no convincing evidence, of course, that such is the case. 



BuRRi, January, 1906. 



Burri's next paper ^ was on ''foul brood" and "sour brood." 

 His discussion of foul brood is quite similar to that which appeared 

 in his former paper (p. 64). We shall therefore direct attention at 

 this time to that portion devoted to "sour brood." 



The origin of the name "sour brood" is indefinite. Quoting from 

 C. P. Dadant, an American writer, Burri writes that there are three 

 diseases of the brood recognized in America — foul brood, sour brood, 

 and black brood. This view would make sour brood synonymous 

 with pickled brood, but as it will be learned later in his work on sour 

 brood, Burri was stud3dng for the most part at least European foul 

 brood. 



In his work Burri did not find a uniformity in the diseased brood 

 examined either in the gross or the miscroscopic appearance. In 

 one sample he found no bacteria, although the outward appearance 

 of the larvae indicated disease. In another sample the gross ap- 

 pearance did not suggest foul brood, and there were absent the bac- 

 teria which are commonly found in the disease; and in their stead 

 there were present mUUons of bacteria which to the investigator did 

 not seem to stand in etiological relation to the disease. In stUl a 

 third instance the larvae gave no outward sign of being killed by the 

 bacteria of foul brood, but when studied culturally, they showed 

 the presence of a very large number of unidentified bacteria together 

 with a few of those which frequently accompany "foul brood." 

 These findings illustrate, he says, some of the difficulties which are 

 encountered in a study of the brood diseases bacteriologically. 



Putting aside all samples w^hich were unquestionably "foul brood," 

 he attempted to group the remaining ones according to certain 

 characteristics observed in a study of the gross appearance of the 

 diseased brood. One character w^hich seemed to be emphasized was 

 the sour odor emitted by certain samples. On account of this he 

 classified this condition as "sour brood." In testing the odor of 

 brood dead of the disease, Burri recommends the holding of the nose 



1 Burri, Dr. R., January, 1906. Bakteriologische Untersuchungen iiber die faulbrut und Sauerbmt der 

 Bienen. Pp. 39, pi. 1. Vorwort by U. Kramer. 



