VIII BIOGENESIS AND ABIOGENESIS 265 



tenth of that of the whole world, and represented a 

 money- value of 117,000,000 francs, or nearly five 

 millions sterling. What may be the sum which 

 would represent the money-value of all the in- 

 dustries connected with the working up of the 

 raw silk thus produced, is more than I can 

 pretend to estimate. Suffice it to say, that the 

 city of Lyons is built upon French silk as much 

 as Manchester was upon American cotton before 

 the civil war. 



Silkworms are liable to many diseases; and, 

 even before 1853, a peculiar epizootic, frequently 

 accompanied by the appearance of dark spots 

 upon the skin (whence the name of " Pe"brine " 

 which it has received), had been noted for its 

 mortality. But in the years following 1853 this 

 malady broke out with such extreme violence, 

 that, in 1858, the silk-crop was reduced to a third 

 of the amount which it had reached in 1853 ; 

 and, up till within the last year or two, it has 

 never attained half the yield of 1853. This 

 means not only that the great number of people 

 engaged in silk growing are some thirty millions 

 sterling poorer than they might have been; it 

 means not only that high prices have had to be 

 paid for imported silkworm eggs, and that, after 

 investing his money in them, in paying for mul- 

 berry-leaves and for attendance, the cultivator has 

 constantly seen his silkworms perish and himself 

 plunged in ruin ; but it means that the looms of 



