46 HISTORICAL NOTES ON BEE DISEASES. 
milit and declared it to be the specific germ of “black brood’’; the 
other he named Bacillus thoracis and thought probably that it modi- 
fied the disease in some way. He said so little about either of these 
species that neither of them can be identified from his writings. In 
his examination of five specimens received from West, he reports 
Bacillus' mili in all of them, Bacillus thorac’s in two, and Aspergillus 
pollini in two. 
In his experimental investigations Howard used two nuclei which 
were free from disease, and fed each of them a culture of ‘‘ Bacillus 
miliz”’ in one-half pint of sirup on November 7, and repeated similar 
feedings on November 10. The feeders were removed from each 
hive on November 12. When the bees were examined on November 
26, no brood at all was found in one of the nuclei. In the other 
nucleus was found no eggs, but larve six or seven days old and con- 
siderable capped brood. Near the outer part of the broad-nest 
apparently some capped cells were found from which were taken 
nearly matured pupx. Other pup, nearly white, with a dark 
spot on the abdomen, were removed, together with others which 
were dark or black all over. ‘‘ Bacillus miliz”” was reported to have 
been found microscopically in nearly every pupa examined. Howard 
states that no uncapped larve seemed from gross appearance to 
be affected, but in the bodies of several of them Bacillus milit was 
found. The two nuclei were again examined on December 14. As 
before, there was nothing wrong apparently with one nucleus. In the 
other nucleus there were about 30 capped cells which contained 
dead pupz that were nearly black. Microscopic examination 
caused him to report the presence of Bacillus mili in all of these 
pupe. 
Tt will be observed that the results which Howard obtained from 
the inoculation of the two nuclei with cultures of ‘‘ Bacillus mili” 
une proved nor disproved the causal relation of “‘ Bacillus mili” 
o ‘‘black brood.” As evidence to support his declaration that 
Boil milit is the specific cause of black brood, modified probably 
at times by Bacillus thoracis, he offers the data that Bacillus mali 
was found in all of the few somnmlles which he examined, and that 
in a few instances Bacillus thoracis was also present. 
In pointing out the differences between ‘‘foul brood,” ‘‘ pickled 
brood,” and ‘‘black brood,’ the following three assertions are made 
by Howard; not one of them, however, has yet been demonstrated 
to be true. 
Foul brood, pickled brood, and black brood. Foul brood, due to Bacillus alvei— 
a specific bacterium. 
Pickled brood, due to Aspergillus pollinis—a specific fungus. 
Black brood, due to Bacillus milii, modified, perhaps, by Bacillus thoracis, specific 
bacteria. 
