206 BIOGENESIS AND ABIOGENESIS viil 



Lyons have lacked employment, and that, for 

 years, enforced idleness and misery have been 

 the portion of a vast population which, in former 

 days, was industrious and well-to-do. 



In 1858 the gravity of the situation caused the 

 French Academy of Sciences to appoint Com- 

 missioners, of whom a distinguished naturalist, 

 M. de Quatrefages, was one, to inquire into the 

 nature of this disease, and, if possible, to devise 

 some means of staying the plague. In reading 

 the Eeport l made by M. de Quatrefages in 1859, 

 it is exceedingly interesting to observe that his 

 elaborate study of the Pebrine forced the convic- 

 tion upon his mind that, in its mode of occurrence 

 and propagation, the disease of the silkworm is, in 

 every respect, comparable to the cholera among 

 mankind. But it differs from the cholera, and so 

 far is a more formidable malady, in being here- 

 ditary, and in being, under some circumstances, 

 contagious as well as infectious. 



The Italian naturalist, Filippi, discovered in the 

 blood of the silkworms affected by this strange 

 disorder a multitude of cylindrical corpuscles, each 

 about -ginnrth f an i ncn l n g- These have been 

 carefully studied by Lebert, and named by him 

 PanhistopTiyton ; for the reason that in subjects in 

 which the disease is strongly developed, the cor- 

 puscles swarm in every tissue and organ of the 

 body, and even pass into the undeveloped eggs of 



1 JSt'tdes sur Ics Maladies actudles dcs Vers a Soic, p. 53. 



