EUROPEAN FOULBROOD. 29 
TI, III, IV), the yellow hue of the larve more recently dead, and 
the brown shade of those longer dead, the irregularity of the brood 
(Pl. I), and the absence of a disagreeable odor. 
Not infrequently, however, the diagnosis is not so simple. During 
recovery from the disease scales (Pl. V, F, 1) of larve dying in 
capped cells may be the only remains of diseased brood to be found, 
all of the younger larve having been removed by the bees. These 
scales! are, as a rule, comparatively few in number and resemble 
somwhat those of American foulbrood, but would rarely be mistaken 
for those of sacbrood. In these cases a diagnosis can be made fre- 
quently by a microscopic examination alone. Cultures, however, are 
needed in some instances. 
Special attention is needed in cases of early infection and in other 
instances where only a small amount of diseased brood in uncapped 
cells is present (Pl. I, A). The symptoms manifested by larve sick 
or only recently dead of the disease furnish often the readiest and 
most conclusive evidence of the presence of the disease. Larve of 
the age at which they comfortably fill the bottom of the cell exhibit- 
ing increased peristalsis-like movements of the body suggest European 
foulbrood. Increased transparency of larve of this age (Pl. II, B) 
is also suggestive. The presence of a white or yellowish-white mass 
within the stomach (midgut) as seen through the dorsal median line 
of the body is strong evidence of the presence of the disease. If 
on puncturing the body of larve nearly dead or only recently dead the 
contents of the stomach flows out as a fluid and more or less finely 
granular mass, the fact furnishes further evidence of European foul- 
brood. 
A symptom which is pathognomonic of the disease is to be seen in 
larve that have been infected somewhat more than two days, but 
wherein the disease has not reached an advanced stage. The test 
(15) involves the removal of the stomach contents, which con- 
sist of a bacterial mass, together with a small amount of larval food 
and a clear envelope (PI. VIII, a, b,c). The slight tension necessary 
to remove the contents stretches the envelope and breaks the whitish 
bacterial mass into a number of fragments. 
1 The number of larve that die of European foulbrood in capped cells after assuming 
the endwise position represents a very small percentage of the brood that dies of the 
disease. These remains may be found in practically all colonies in which the disease has 
been present for a sufficiently long period and in which a considerable amount of dead 
brood has resulted. Before becoming dry they are somewhat viscid and are less easily 
removed than are those of larve dying at an earlier age. These and the scales resulting 
from them are used in diagnosis principally (1) when the younger larve sick or dead of 
the disease have been removed, (2) when a demonstration of the presence of Bacillus alvei 
is desired, and (3) when both European foulbrood and American foulbrood infection is 
suspected. Such a double infection has been encountered in the writer’s experience very 
rarely. In making diagnoses, therefore, after European foulbrood has been found in 
the sample American foulbrogd is seldom looked for. 
