DISEASES OF SILKWORMS 49 



of reproduction. At that stage, the microscope 

 shows it with absolute certainty, even if the seed 

 and the worms appeared very healthy. The practical 

 result is You have a roomful of silkworms : it 

 has done well, or ill, or fairly well : you want to 

 know whether to steam the cocoons and send them 

 to be unwound, or keep them for reproduction. 

 Nothing easier. Raise their temperature, hasten 

 the coming out of a hundred or so of the moths, 

 examine them under the microscope : that will tell 

 you what to do. And the thing is so easy to 

 recognise that a woman or a child could be trusted 

 with it. I admit that the seeding may be in the 

 hands of some countryman, with no chance of his 

 settling the point then and there : but, instead of 

 throwing away the moths after mating and laying, 

 he can put a large number of them, just as they 

 happen to come, in a bottle half full of spirit, and 

 send them to a research bureau, or to some man of 

 experience : and thus we should have a whole year, 

 if we wanted it, to judge the worth of the seed 

 which will have to be taken in hand next spring." 



It was in 1866, also, that he proved the contagious- 

 ness of the disease, by feeding worms on mulberry- 

 leaves smeared with the corpuscles. 



In January, 1867, he was again at Alais, with 

 his assistants, and with Madame Pasteur and his 

 only daughter. He quickened a mere matter of 

 temperature the hatching of last year's seed : he 

 found his prophecies coming true. He used to 

 begin work at dawn, and work all day. Then 

 came his discovery of other ways of contagion, 



7 



