Mar. i2,1917 
Spore-Forming Bacteria of the Apiary 
417 
mal larvae were found to be nearly always sterile. This fact was pointed 
out by White in 1906 (16, p. 16, 29). 
The writer has found occasionally a few organisms, both of B. vulgatus 
and B. mesentericus , on culturing apparently healthy larvae, and on still 
rarer occasions a very large number in a single larva. This should excite 
no surprise when the great abundance of both of these organisms in nature, 
especially in water, is considered. Another method of determining the 
presence of the bacteria in the larvae is by the study of paraffin sections. 
Larvae were not sectioned from every colony inoculated, but enough 
sections were secured to show that the organisms were present in great 
Fig. 6.— Bacillus pluton: Smear direct from a diseased larva. X 1,480. Note that the organism stains 
uniformly, this distinguishing it from any spore-forming bacterium of the apiary. 
abundance in the alimentary canal of the larvae. It was hoped by sec¬ 
tioning larvae and pupae, as well as the shed skins and detritus in the bot¬ 
tom of the cell, that the ultimate fate of the bacteria in the gut of the bee 
might be learned. The results of such investigations are not definite 
enough for publication at this time. Indications point to the elimination 
of the bacteria some time after the brood passes to the pupal stage, since 
so comparatively few organisms were ever recovered from culturing the 
contents of pupae, especially later pupal stages. 
RESULTS OF THE INOCULATIONS 
In none of the colonies inoculated over the whole five seasons of feeding 
of the cultures was there any appearance of the brood simulating either 
