PREFACE 



IN investigating the diseases of silkworms in India I have kept 

 three things in mind — first the practical rather than the academic 

 point of view ; second the historical standpoint, and third the results 

 got in other countries, especially the tropics, as well as in India. 

 Because of the first of these I have left out in this report all questions 

 of a purely scientific interest.^ I hope to publish later in one of the 

 scientific journals the results of my work on the life-history of the 

 parasite that causes pebrine. Because of the second I have always 

 discussed at some length the early work, especially that done in 

 India, for only by paying due attention and respect to the older 

 wofkers can one expect to get a true and complete view of any 

 problem. Indeed, the work of the earlier investigators is very 

 frequently on a much higher plane than our modern efforts : they 

 were not so eager to get out results and so could spend more time 

 in thinking over them. Because of the third I have not multiplied 

 experiments. If I found that my results confirmed those of other 

 workers I have not delayed further over them, believing that a 

 fairly rapid survey of the field was more called for than a pains- 

 taking re-investigation of any particular point. I have written as 

 simply as possible in order that my report might be intelligible to • 

 those who have no special knowledge of the subject: experts, if 

 any should read it, will doubtless pardon any apparent " insults " 

 to their knowledge. 



I am deeply indebted to many people for assistance in carrying 

 out this piece of work, but especially to the sericultural departments 

 of the different provinces and States in India. From all I have 

 received the utmost courtesy and assistance while touring in their 

 districts, and they have shown the greatest kindness in replying to 

 my inquiries. I have to express a special degree of indebtedness 

 to Mr. P. C. Chaudhury, Deputy Director of Sericulture in Bengal, 

 and to the staff of the Berhampore Central Nursery for having 

 conducted experiments for me in the nursery and for having got 

 rearers in the villages to rear worms for me specially. To all who 

 sent cocoons for census purposes I wish to convey my thanks. 

 For the photographs which illustrate several of my experiments 

 I wish to thank Mr. Walton, Officiating Imperial Agricultural 

 Bacteriologist, and for most of the drawings and text-figures I am 

 indebted to Mr. K. D. Das and Mr. N. N. Bagchi, two of the 

 artists on "the Pusa staff. Finally, I would record my apprecia- 

 tion for the way in which my assistants, Mr. Harihar Prasad and 

 Mr. C. B. Sahaya, have helped me in my work, and I would also 

 name my head rearer, Lotan. 



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