312 OTHER GERM DISEASES 
than an inflammation; it gives rise to a general decay of the tissues 
attacked (called necrosis) and, since it attacks many parts, it 
has a variety of effects. In the skin it causes numerous infamma- 
tory diseases. It produces the foot rot of sheep and also of cattle. 
It attacks the bones in the nose, causing their destruction; it 
may bring about troubles in the alimentary canal, and it is the 
source of some of the cases of hog cholera, as well as several 
other affections. 
Foul Brood of Bees (B. alvez and B. larve).—Foul brood is 
a disease attacking the larvae: of bees while still within their cells 
causing them to become sickly and eventually killing them and 
producing a decomposition of the body. The hive becomes 
vile-smelling from the decomposition and the whole economy of 
the hive is interrupted. The bees fail to collect honey and the 
hive may beruined. There are really two different diseases going 
by this name, the American and the European foul brood, re- 
sembling each other and yet being easily distinguished. Both are 
produced by bacteria, the European by B. alvez and the American 
by B. larve. In this country the latter is the more common, 
though both are found. Both diseases are readily carried from 
hive to hive. Sometimes this is done by robber bees that steal 
honey from hives, and sometimes it is carried by the bee-keeper 
who handles a diseased colony and then a clean colony, or who 
places in a clean hive honey or combs from an infested hive. Its 
very infectious nature should be thoroughly appreciated by the 
bee-keeper and great care should be taken in handling bees. It 
is also doubtless carried from locality to locality by the custom 
of selling bees. The two diseases are widespread over America, 
Europe, Africa, and Australia. It spreads rapidly, sometimes 
infesting a whole district in the course of a single season so as 
nearly to ruin the industry of the bee-keeper. 
DISEASE CAUSED BY UNKNOWN PARASITES 
The causes of several well-known diseases have not yet been 
discovered; nevertheless it must be recognized that they are 
