STUDIES OF 1866 161 



ought to give, as regards the influence of the corpuscles 

 of the father and of the mother upon the result of the 

 industrial culture, or of the culture for eggs, information 

 which could not fail to be very important, whatever 

 might be the true significance of the corpuscle itself. 

 In fact, advancing with this light, Pasteur perceived 

 immediately a certain number of facts of the greatest 

 importance. 



The first fact was that on a large scale in the industrial 

 culture the batches of eggs behaved worse and worse, 

 that is gave less and less cocoons, in proportion as the 

 parents were more and more occupied by corpuscles. 

 This sufficed to establish between the existence or the 

 number of the corpuscles and the presence of the disease, 

 the bond of union which was the first need of the new 

 method. 



The second fact was that eggs laid by corpuscular 

 moths were not, per se, destined to miscarry, and might 

 develop good cocoons giving acceptable yields. Such 

 was, for example, the case of the eggs received from 

 Japan, which, although corpuscular, were nevertheless 

 much sought after by silk-growers. This robust race 

 seemed better to resist the prevalent disease. Such was 

 also the case for several cultures of French races. But 

 none of these cultures, even those which had yielded the 

 greatest number of cocoons, could give good eggs, 

 because all the moths were strongly corpuscular. This 

 explained why one sometimes miscarried in selecting 

 eggs derived from a successful culture. The success 

 of this culture proved nothing as to the egg. In addition, 

 control by means of the microscope was necessary. 

 And so one came back to the method of egg-selection, 

 authoritatively recommended by Pasteur, this being 

 brought forward once more, singularly strengthened 

 by its first trial. 



