THE SILKWORM-DISEASE. 143 



of the standard lot were clearly in much the best 

 health. On examining the infected worms through 

 a magnifying glass, a multitude of little spots were 

 discovered on their heads, and on the rings of their 

 bodies, which had not before shown themselves. These 

 spots appeared on the exterior skin when the interior 

 skin of the intestinal canal contained a considerable 

 number of corpuscles. It was these corpuscles that 

 impeded the digestive functions, and interfered with 

 the assimilation of the food. Hence arose the in- 

 equality of size of the worms. After the fourth moult- 

 ing, the same type of disease was noticed as that 

 which was breaking out everywhere in the silkworm 

 nurseries, especially the symptom of spots on the 

 skin, which had led to the disease being called pebrine. 

 The peasants said that the worms were peppered. 

 The majority of the worms were full of corpuscles. 

 Those which spun their cocoons produced chrysalides 

 which were nothing but corpusculous pulp, if such 

 a term be allowed. 



It was thus proved that the corpuscles, introduced 

 into the intestinal canal at the same time as the food 

 of the worms, convey the infection into the intestinal 

 canal, and progressively into all the tissues. The 

 malady had in certain cases a long period of incuba- 

 tion, since it was only on the twelfth day that it be- 

 came perceptible. Finally, the spots of pebrine on 

 the skin, far from being the disease itself, were but 



