THE SILKWORM-DISEASE. 135 



other ideas than those which come to you from your 

 own observations.' 



Pasteur allowed himself to be persuaded, less by the 

 force of these arguments than by the desire to give 

 his illustrious master a proof of his profound deference. 



As soon as the promise was given and the resolu- 

 tion made to go to the South, Pasteur thought over 

 the method to be employed in the pursuit of the 

 problem. Certainly, amidst the labyrinth of facts and 

 opinions, it was not hypotheses which were wanting. 

 For seventeen years they had been rising up on all 

 sides. 



One of the most recent and the most comprehen- 

 sive memoirs upon the terrible epidemic had been 

 presented to the Academy of Sciences by M. de Quatre- 

 fages. One paragraph of this paper had forcibly 

 struck Pasteur. M. de Quatrefages related that some 

 Italian naturalists, especially Filippi and Cornalia, 

 had discovered in the worms and moths of the silk- 

 worm minute corpuscles visible only with the 

 microscope. The naturalist Lebert affirmed that 

 they might always be detected in diseased silkworms. 

 Dr. Osimo, of Padua, had even perceived corpuscles 

 in some of the silkworms' eggs, and Dr. Vittadini had 

 proposed to examine the eggs with a microscope in 

 order to secure having sound ones. M. de Quatre- 

 fages only mentioned this matter of the corpuscles as 



