OTHER DISEASES OF DOMESTIC 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-liko 

 form (Bacillus'), but in that of a small protoplasmic 

 mass, with amoeboid movements, a characteristic not 

 observed in any bacterium (Balbiani). 



The other species of silkworms which have been 

 recently introduced, notably the oak silkworm from 

 Oiiina (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 



