48 HISTORICAL NOTES ON BEE DISEASES. 
Harrison, DECEMBER, 1900. 
The next paper to be considered is one by Harrison.t In comment- 
ing upon the work of Cheshire and Cheyne, he asserts that these men 
established the causal relation of Bacillus alvei to foul brood by 
successfully applying Koch’s rules in their work. He rehearsed in 
his paper the spraying experiment which Cheshire was supposed to 
have done and stated that since that time Bacillus alvei has generally | 
been regarded as the cause of the disease. 
In the beginning of his work, then, Harrison, like Mackenzie, 
accepted the work of Cheshire and Cheyne as conclusive that Bacillus 
alver is the cause of foul brood. It is very unfortunate that these 
two men should have made this mistake, as their papers have had 
the effect of strengthening two erroneous ideas: First, that the two 
maladies which together were known as foul brood were one disease; 
and second, that Bacillus alvei is the cause of the disorder. 
Harrison was aware of the fact that some bee keepers believed 
that there was more than one disease included under the name foul 
brood, since, in commenting on the work of Dickel and Klamann, he 
states that Dickel writes of one form of the disease which affects 
the unsealed brood, and of another form which affects the sealed, 
and even a third form, a mixed form which seems to be still more 
malignant. He states furthermore that Klamann suspected two 
kinds of disease. 
Harrison entertained the following ideas concerning foul brood. 
The disease affects chiefly the larve, and when they are attacked 
they no longer lie curled up in the cell but are extended in it or move 
about unnaturally. The adult bees by asort of inertness which seizes 
them may at this time show symptoms of the disease. The affected 
larvee become flabby and die, and as a result of the decomposition 
which sets in, the decaying mass takes on a yellowish color. The 
yellow turns to a brown and when touched by a pin at this time or 
later, a portion of the mass may be pulled out in a long, ropy, tena- 
cious string. This ropy mass dries down gradually to a brown scale 
which adheres to the wall of the cell. The bees as a rule are not 
-active in removing larve dead of this disease from the cells, but, on 
the contrary, they are quite inactive, without desire to fly, but they 
may be seen fanning at the entrance of their hive. At this time a 
foul odor may be detected coming from the hive. The phase of the 
disease which some authors discuss as being a different form, Har- 
rison states, is the same disease but that the larve die after being 
capped over instead of before. The capping of the cells containing 
such larvee becomes indented or sunken and finally perforated. By 
Experimental Farm. Pp.32. Toronto. Portions of this bulletin are quoted in Bulletin No. 70, Bureau 
of Entomology, U. S. Department of Agriculture, pp. 23-26. = 
