DISEASES AND ENEMIES. 
555 
cut in it. Those exposed to the spray were in part 
removed by the bees ; the rest died, passing through 
all the changes observed in foul brood [Bacillus 
alvei') y and were found full of bacilli ; while the 
screened larvae matured in health, proving incontest- 
ably that the bacillus is the cause of the disease. 
This is further corroborated by all the cultures giving 
off the exact odour of an infected stock. 
Two other characteristics of this particular bacillus 
need mentioning : First, the extraordinary and unique 
size of the spore, which is about 2xJ^in- wide and 
- i - ^ - QQ - o in. long. These, when stained, if examined by a 
first-class or -^in., can be measured and identified 
immediately after removal from the body of the bee, 
or when found in coffee-coloured material. It is thus 
that Bacillus alvei can be pronounced upon at once. 
The second peculiarity is observed when the cultures 
are made in agar agar, when the spores are formed 
in line, as at F, Fig. 122. As already remarked, they 
also lie in this order in the tissues of the insect ; but 
to display them thus requires great address and much 
patience.* 
We have now to consider the means of propagating 
the disease. It has been confidently asserted that the 
honey is the seat of the contagium, and that bees 
carry the disease into their hives by robbing. Of 
course, this positive assertion has no better proof than 
the equally false supposition that the disease only 
For further information, see the “Pathogenic History', and History 
under Cultivation, of a New Bacillus {Baciilus alvei)," by Frank R. 
Cheshire, F.R.M.S., F.L.S., and Watson Cheyne, M.B., F.R.C.S., 
&c. {Journal of the Royal Microscopical Society, August, 1885). 
