TKOCEEDINGS OF THE TIIIHD ENTOMOLOGICAL MEETING 817 



slow in winter. In cold countries they multiply slowly but in hot coun- 

 tries they multiply rapidly. {Vide Pu^a Bulletins, Nos. 48 and 74.) 



We hope that Mr. HutchinSon, by his further researches, will be 

 able to find out a method which is more economical and effective than 

 the Pasteur method. 



Comparison and Ceiticism of the Various Methods. 



The Pasteur method. It is Simple, effective and economical. The 

 tnoths are crushed by boyS and girls after a week's practice. In France 

 and in some places in Japan crushing machines containing about 100 

 •small mortars and pestles are used for crashing 100 moths at a time. 



The double Zero of Italy. It is a simple, effective but does not appear 

 to be as economical as the Pasteur method because the eggs of a healthy 

 mother but a pebrinized father which cannot transmit the disease to 

 the progeny are also thro\\ai away. This method can be found suitable 

 for improving and regenerating a rajse. 



The Industrial methods. All industrial methods are very simple 

 ' and " economical " but they are not effective at all. Industrial eggs 

 contain pebrine spores and they are not safe to rear as cocoon crops 

 may fail because it is not known to what extent the eggs are 'pebrinized. 



The Bengcd method as modified by Mr. Mukerji. It is very simple 

 and " economical " but not so effective as the Pasteur system because 

 all the parts of the moths are not crushed well and cover glasses are 

 not used at the time of examining the juice. Pebrine spores escape 

 notice if they are in the uucrushed parts when the infection is very 

 •mild. The moths can be crushed by ordinary labourers after a few 

 days' practice and an ordinary microscopist can examine 800 — -1,200 

 moths in a day of eight hours if he is supplied with a microscope which 

 is provided with a " rough adjustment screw." 



The modified method of Pasteur as recommended by Mr. Hutchinson. 

 The method is laborious and is not economical. The System does not 

 seem to be more effective than the Pasteur method. An overseer must 

 be trained to remove the gut. It takes time to take out a minute part 

 of it on the slide with a needle. There will be waste of eggs as about 

 10 per cent, of the moths are to be thrown away if they are decom- 

 posed or dried up because it would not be possible to distinguish their 

 guts. An irresponsible overseer can take out any part of the body lohich 

 is free from pebrine, instead of the mid-gut when the infection is very mild 

 there but acute in the ovaries and pass the diseased moth as healthy. 

 The only advantage in this system is that when the infection is mild 

 in the mid-gut it will take little time and attention for the detection of 

 the Spores whereas according to the Pasteur method more time and 



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