THE SILKWORM-DISEASE. 137 



himself in a little house three kilometers from Alais. 

 Two small cultures were there going on ; they were 

 nearly the last, the cocoons had all been spun. One 

 of these cultures, proceeding from eggs imported that 

 very year from Japan, had succeeded very well. The 

 other, proceeding also from Japanese eggs which had 

 been reproduced in the country, had arrived at their 

 fourth moulting and had a very bad appearance. 

 But, strange to say, on examining with the microscope 

 a number of chrysalides and moths of the group which 

 had so delighted its proprietor, Pasteur found cor- 

 puscles almost always present, whereas the examina- 

 tion of the worms of the bad group only exhibited 

 them occasionally. This double result struck Pasteur 

 as very strange. He at once sent messengers into all 

 the neighbourhood of Alais to seek for the remains of 

 backward cultivations. He attached extreme impor- 

 tance to ascertaining whether the presence of corpus- 

 cles in the chrysalides or moths of the good groups, and 

 the absence of the same corpuscles in the worms of the 

 bad groups, was an accidental or a general fact. He 

 soon recognised that these results did very frequently 

 occur. But what would happen when the worms of 

 the bad group spun their cocoons? Pasteur found 

 that in the chrysalides, especially in the old ones, the 

 corpuscles were numerous. As regards the moths 

 proceeding from these cocoons, not one was free from 

 them, and they existed in profusion. 



