r*; 



114 SCIENTIFIC REPORTS OF THE AGRICULTURAL RESEARCH 



REPORT OF THE PROTOZOOLOGIST. 



(A. Pringle Jameson, D.Sc.) 

 I joined my appointment at Pusa on 17th October. 

 1919, but considerable inconvenience and delay were ex- 

 perienced in getting the work on silk-worm diseases pro- 

 perly started on account of the extreme slowness with 

 which the apparatus ordered at home was delivered — 

 although ready for dispatch in September 1919, the last 

 consignment was not received until April 1920 — and also 

 on account of the lack of assistants, sanction for staff not 

 having been received until May. If it had not been for the 

 kindness of Mr. C. M. Hutchinson and other 'heads of 

 Sections who lent me sufficient assistance and apparatus to 

 go on with, it would have been practically impossible to have 

 started certain lines of work. 



The first silk-worm disease that is being investigated is 

 pebrine. This disease is caused by a very minute pro- 

 tozoan parasite. Sixty years ago the silk industry in 

 Europe was nearly extinguished by it and fears are enter- 

 tained lest it should assume equally serious proportions in 

 India. The work on this disease was initiated by Mr. 

 Hutchinson and it is being carried on from the point where 

 he left off. It falls naturally into two parts. First the 

 investigation of the life-history of the parasite, Nosema 

 bombycis, which causes the disease, and second the investi- 

 gation of means of controlling the disease. The second 

 line of inquiry is, of course, more or less dependent on the 

 results of the first. 



(a) Life-history of the parasite. Attention is being 

 paid at present to the early stages of the life-history — the 

 behaviour of the spores when introduced into the gut of 

 the silk-worm and the initial attacks of the parasite on 

 the tissues of the host. This work is very difficult to carry 

 on in the hot weather as much of it entails the cutting of 

 extremely thin paraffin wax sections, but already a con- 

 siderable amount of information has resulted from this line 

 of investigation. It is, however, much too early in the in- 



