70 REPORT ON THE DISEASES OF SILKWORMS IN INDIA 



The identification of these everyday bacteria is not always very 

 certain as the descriptions given are not satisfactory. Details of 

 the organisms are given in Appendix IV. I have there given what 

 I believe to be the correct names for them, but while the bacilli 

 are probably correctly diagnosed the descriptions of the micrococci 

 to which I have had access are so insufficient that I am not at all 

 satisfied with any names which can be given to them. As will 

 be seen, my Bacillus A is probably B. megatertum var. hombycis, 

 Bacillus B is B. mycoides and Bacillus C is B. coli. Four of the 

 micrococci I isolated are perhaps the same as those got by Sasaki 

 (1910) from caterpillars suffering from grasserie, but I cannot quite 

 identify those of Sawamura (1902-03). The details are, however, 

 given in the Appendix mentioned. 



The work of Sawamura (1902-03) showed clearly that the most 

 potent exciting causes of flacherie were high temperature, high 

 humidity and bad ventilation — the last being to some extent at 

 least the cause of the first two. I have been able to confirm this 

 view to some extent. Other causes are said in practice to give 

 rise to outbreaks of flacherie, some of these are dirty leaf, wet 

 and fermented leaf, coarse leaf, overfeeding, overcrowding, etc. 

 Attempts were made to bring about flacherie by some of those 

 means without any success. According to Mukerji, Chhotapolu 

 worms are peculiarly liable to flacherie, and for this reason these 

 worms were chosen for these experiments and further these worms 

 were hatched from eggs laid by a highly pebrinised moth. In 

 short, nothing was left undone that might have brought about an 

 onset of the disease. As will be seen from Experiment 27, there 

 was not a single case of flacherie in any of the lots. An attempt 

 was made to see if making the caterpillar gut acid would cause 

 flacherie. Very weak acids had no effect but when the leaf fed to 

 the caterpillars was first soaked in 10 per cent, hydrochloric acid 

 and then fed to the worms, on one occasion all died of flacherie 

 (Experiment 28, lot 4). The worms in this lot showed every symp- 

 tom of flacherie and cultures made from the gut gave abundant 

 growths of Bacillus A. At the same time worms were similarly fed 

 on leaf treated with ammonium hydrate. Five per cent, ammonium 

 hydrate gave two cases of flacherie while 10 per cent, gave no 

 results. Cultures made from the guts of the dead caterpillars in 

 this case gave numerous colonies of Micrococcus a and a very few 

 Bacillus A. When the experiment with the 10 per cent, hydro- 

 chloric acid was repeated no cases of true flacherie were got. "The 

 amazing thing in this experiment was that when the caterpillars 

 showed symptoms of disease the gut content was highly alkaline 

 (pH=9 - 8) despite the fact that the worms were eating strongly 

 acidulated leaf. The gut juices had obviously neutralized the acid 



