CHAPTER XI 



MICROSPORIDIOSIS BEE AND SILKWORM 

 DISEASES 



AMONG the romances of Science, few are of 

 greater interest and economic importance than 

 those centring round the name of Pasteur, and one 

 of his researches was the means of saving an entire 

 industry that of the preparation of raw silk to 

 France. Pasteur it was, who identified small oval 

 bodies found in the corpses of silkworms as the 

 cause of their death. He also showed that the 

 moths, when infected, could transmit the same 

 disease to the eggs, and that the young were born 

 infected. The fatal disease pebrine which devas- 

 tated the silkworm-rearing establishments of France, 

 was first identified by Pasteur with the animal 

 parasite now known as Nosema bombycis. It was 

 due to his ingenuity that preventive measures were 

 devised ; for, by microscopical examination of the 

 parents, and by comparing the weight of diseased 

 and healthy eggs, it became possible to destroy the 

 infected ones and to preserve only healthy stock. 

 Pasteur's work was, however, incomplete, for the 

 life-history of the parasite and the method of its 



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