92 REPORT OF THE AGRICULTURAL RESEARCH INSTITUTE 



good strains of yeast and for the training of distillers' 

 assistants in their proper use. 



Pebrine. At the request of Mr. Lefroy, Imperial Silk 

 Specialist, an investigation of the conditions of incidence 

 of this disease of silkworms in India was undertaken. The 

 primary object of the enquiry was to determine whether 

 the failure to avoid disease in India by using the Pasteur 

 method of selection of disease-free " seed " is due to any 

 inherent inapplicability of the method to Indian condi- 

 tions, or merely to its improper use in this country. So 

 far as the enquiry has proceeded it appears that both these 

 factors come into play in Bihar and Bengal. The Pasteur 

 method depends upon the examination of the parent moth 

 and the rejection of eggs from those found infected; the 

 standard method of examination devised by Pasteur and 

 used with success in Europe but with less certainty in 

 India, allows of microscopic examination of a drop of the 

 fluid obtained by crushing the whole moth without distinc- 

 tion of parts, it being assumed that the disease producing 

 pebrine bodies will exist in such numbers in the diseased 

 insect at this stage of its growth as to make certain of their 

 occurrence in any sample of the body fluids taken for 

 examination. This, however, has not been found to be the 

 case with the pebrine-infected moth of the multivoltine 

 mulberry silkworm as used in this part of India. Examin- 

 ation in the ordinary manner in many cases has failed to 

 find the pebrine bodies, whereas examination of the lining 

 tissues of the intestine of the same specimens has revealed 

 their presence, the diseased condition being subsequently 

 confirmed by the development of pebrine in a high percent- 

 age of the larvae reared from the eggs of the moths so 

 affected. It is clear therefore that in India, the standard 

 method of examination fails to eliminate all diseased eggs, 

 and in order to be at all certain of this being done it will 

 be necessary to alter the method and unfortunately to make 

 it more difficult and more laborious, although not at all 

 outside the range of capability of the class of workers at 

 present engaged in selection. In parts of Bengal, the con- 



