OTHER DISEASES OF DOMESTIO ANIMALS. 153 
Cornalia. They closely resemble the spores of some 
bacilli (B. amylobacter, for instance), and their germi- 
nation is likewise effected by perforation of the spore 
at one end, and issue of the protoplasm from the 
interior. This, however, does not issue in a rod-like 
form (Bacillus), but in that of a small protoplasmic 
mass, with amceboid movements, a characteristic not 
observed in any bacterium (Balbiani). 
The other species of silkworms which have been 
recently introduced, notably the oak silkworm from 
China (Attacus Pernyi), are attacked by microsporidia 
analogous to those of pebrine. 
Pasteur has indicated the mode of averting the 
ravages of this disease. He has thus addressed the 
breeders: “If you wish to know whether a lot of 
cocoons will yield good seed, separate a portion of them 
and subject them to heat, which will accelerate the 
escape of the moth by four or five days, and examine 
them under the microscope to ascertain whether cor- 
puscles of pebrine are present. If they are, send all the 
cocoons to the silk factory. If they are not diseased, 
allow them to breed, and the seed will be good and 
will hatch out successfully. In a word, start with 
absolutely healthy seed, produced ‘by absolutely pure 
parents, and rear them under such conditions of 
cleanliness and isolation as may ensure immunity 
from infection.” 
When the disease is developed, fumigation with 
sulphurous acid is recommended, or preferably with 
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