BURRI, JANUARY, 1906. 69 
very near the combs, or, better, the removal of a larva and testing 
it. He calls attention to the fact that “foul brood’’ (American foul 
brood) and “sour brood’? (European foul brood) have probably 
often been confused by bee keepers of little experience and placed 
under one name, ‘‘foul brood.’’ 
Another point of difference between ‘‘foul brood” and ‘‘sour 
brood,” as pointed out by Burri, is in relation to the consistency of 
the dead larve in the two conditions. In ‘‘foul brood,’ he says, a 
uniform ropy mass is all that remains of the decaying larva dead of 
the disease, while in ‘‘sour brood” the chitinous covering of the 
decaying larva permits its removal as a whole from the cell. 
Besides the odor and consistency of the dead brood, Burri refers 
to the color as a third characteristic that serves to aid in the differ- 
entiation of ‘‘foul brood” and ‘‘sour brood.” He writes that the 
larvee of ‘‘foul brood” are cream colored soon after the development 
of the bacteria has begun, but later are a pale coffee brown, and finally 
a dark brown. In ‘‘sour brood,” he says, the larve become discol- 
ored. At first they are a dirty yellow. The dry scales are less black 
than those of ‘‘foul brood.”’ 
Burri received samples which were reported to him to be ‘‘black 
brood.” The older larve seemed to be affected and the microscopic 
and cultural examinations gave negative results. This strongly sug- 
gests that this is not the condition to which the term ‘‘black brood” 
has been referred in America. No conclusion was reached by him 
as to the cause of this trouble. Certain differences were noted by 
Burri between the descriptions by Dadant of the different brood dis- 
eases and his own observations. It is not difficult to understand why 
such differences should exist when one recalls that so many descrip- 
tions of the brood diseases in the past by Americans have been based 
largely upon faulty work. 
Further on in his paper, Burri gives the microscopic findings and 
describes the gross appearance of a few larve taken from each of the 
eight samples of sour brood which he examined. He mentions in 
“sour brood” the yellowish color of the larve, the uncapped cells, 
and the presence of rather long reds. Short rods were also found, 
resembling in morphology Bacterwum giintherr. On account of this 
similarity, in recording the presence of this latter species, Burri has 
referred to it as the ‘‘giintheri-forms.’’ These facts concerning the 
eross appearance of the microscopic findings in ‘‘sour brood”’ suggest 
strongly that the condition is the same as the foul brood of Cheshire 
and Cheyne (European foul brood). 
In summing up the results of his study on ‘‘sour brood,” Burri 
emphasizes two observations: First, that there is a form of disease 
found all over Switzerland which possesses the characters mentioned 
for ‘‘sour brood”’; and, second, that in the condition there is a certain 
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