132 SCIENTIFIC REPORTS OE THE AGRICULTURAL RESEARCH 



activity of a high order which is liable to make the spread 

 of the disease even more rapid than was the case in Europe 

 in the middle of last century, when the silk industry was 

 very nearly destroyed, and it is all the more necessary to 

 adopt the strictest measures to prevent such an occurrence 

 in this country. It seems probable that the climatic condi- 

 tions which enhance the activity of the parasite have a 

 compensating action in reducing the length of time during 

 which the spores retain their infective power, and it may 

 be that this factor has been the only one which has so far 

 prevented the disease from wiping out the Indian silk 

 industry altogether. It should be remembered, however, 

 that this factor only affects the spread of the disease by 

 contaminative infection, and does not at all reduce the here- 

 ditary transmission, which is certainly of equal importance. 



The viability of pebrine spores was further tested and 

 the-results of the experiments showed clearly that under 

 moist conditions such spores rapidly lose vitality, whereas 

 in dry air, even at high temperatures, their viability is 

 retained for considerable periods of time. 



The reliance which has been placed upon copper sul- 

 phate as an antiseptic for rearing houses was shown to be 

 based on theory rather than observation, as 75 per cent, 

 infection was obtained with pebrine spores treated with 1 

 per cent, copper sulphate solution, whereas 1 per cent, 

 formalin secured complete immunity under similar condi- 

 tions. 



At the request of the Government of Mysore I visited 

 the State in January and inspected typical rearing estab- 

 lishments, both Government and private. Demonstrations 

 were given of the revised method of examination of moths, 

 and a report was subsequently written embodying a series 

 of suggestions as to the best method of securing adequate 

 and reliable supplies of disease-free seed, and of diminish- 

 ing the amount of contaminative infection during rearing. 

 These suggestions have been adopted by the Sericultural 

 Department of the State. 



