IS THE CORPUSCLE THE CAUSE OF THE DISEASE? 165 



seeing worms inoculated with corpuscular materials die 

 rapidly and yet not contain corpuscles, we still under- 

 stand how Pasteur may have been able to believe that 

 the corpuscles not only were not the cause of the disease, 

 but were not even the constant sign of the disease, and 

 could be absent when the disease was in too rapid evolu- 

 tion, for example, when the substance relied upon to pro- 

 duce it had too active toxic qualities and killed the 

 worm too quickly, as was apparently the case in these 

 two experiments; 



3. ''I have not been able," continues Pasteur, "to 

 discover up to the present time a mode of reproduction 

 of the corpuscle, and its manner of appearance makes 

 it resemble a product of the transformation of the tis- 

 sues." Here Pasteur paid the penalty of his inexperi- 

 ence in the world -of beings to which the corpuscle be- 

 longs, a world where the forms of reproduction are quite 

 other than in the world of microbes, which he knew the 

 best. Without entering into details, we must know that 

 the corpuscle, instead of increasing by segmentation or 

 by budding as do the bacilli or the yeasts, can, under 

 certain circumstances, swell up into a voluminous proto- 

 plasmic mass with almost invisible contours. This in- 

 sinuates itself into the tissues, penetrates them with an 

 almost invisible network in which then only begins the 

 process of delimitation which divides it into distinct 

 and sharply contoured corpuscles. From the initial cor- 

 puscle we have come to some thousands of identical 

 corpuscles, children of the same father. Pasteur had 

 indeed seen this phenomenon of the organization of a 

 sort of amorphous matrix. He described it with a 

 marvelous precision because he was a master observer. 

 He pointed it out to his draftsman, Lackerbauer, who 

 strove to represent it in two plates (pp. 28 and 64). But 

 he does not know how to interpret it, and, as he sees 



