PROCEEDINGS OF THE THIRD ENTOMOLOGICAL MEETING 833 



My experience shows that there are many cases met with where 

 pebrine would go undetected if the gut is not properly examined. As 

 a matter of fact, Mr. De has admitted this indirectly in the course of 

 his paper. The paper said that in about 95 per cent, of the moths he 

 finds more pebrme in the gut than in the body-juice. He says that 

 in a very few cases one or two pebrine spores were detected in the gut 

 and not a single one in the body-juice. 



Then what about these few cases ? Would they not go undetected 

 if Mr. Hutchinson's method was not employed ? 



Again, he says that in rare cases he noticed one or two pebrine spores 

 in the body-juice but not in the gtit. Can it be explained where did these 

 one or two pebrme spores come from? I do not know whether " few 

 cases " are more than " rare cases." 



In order to avoid the colon content Mr, De suggests the use of incuba- 

 tors- and caustic potash. Will it not be dijQ&cult in practice to incubate 

 the moths keeping the same number on the egg card as also on the bags 

 in which the moths are to be dried ? The use of caustic potash makes 

 the pebrine spores look dull. 



However, Mr. De admits that Mr. Hutchinson's method is an 

 efl&cacious one but he thinks it is a slower method. He also speaks 

 of irresponsible overseers who may not work properly. I think where 

 Governments are anxious to eradicate the disease the question of slowness 

 does not come in, especially in view of the sureness of the method. He 

 admits that this method enables the examination of the moths to begin 

 earlier. He admits that the only advantage in this method is that when 

 infection is mild in the mid-gut it will take little time and attention for 

 the detection of the spores, whereas according to Pasteur's method more 

 time and attention will be required and in a few cases spores may go 

 unnoticed if not treated with caustic potash. My experience shows 

 that in the multivoltine races in India many cases will go undetected 

 if examined by the rough method which is in almost all cases possible in 

 the crushing method. 



Professor N. G. Mukerjee, who made a thorough study of the para- 

 site in France and in India, distinctly says on page 57 of his Handbook of 

 Sericulture that " if a silkworm gets the pebrine germs the day before 

 it is ready to spin cocoons and if it is examined in the moth stage on the 

 fifth day the germs get only fourteen days to develop themselves. Unless 

 pebrine is associated with Flacherie, corpusculation does not take place 

 in fourteen days and the moth may be passed as disease free, though 

 full of pebrine." 



I think for such cases gut examination is the only remedy. 



Mr. De says that spores will be found in sufl&ciently large numbers. 



