318 Illinois State Laboratory of Natural History. 



minute spherical granules from .5 ^ to .7 ^ in diameter, staining 

 with aniline fluids, although sometimes with difficulty, and less 

 highly refractile than ordinary micrococci ; second, a great 

 degeneration of the mucous membrane of the chiliferous 

 stomach producing before death a marked diminution in the 

 thickness of the epithilial layer ; and third, the appearance in 

 the alimentary fluids, and usually also in the blood, of spheri- 

 cals and ovals (especially the former), presenting every char- 

 acteristic of unmistakable micrococci. Few if any of the blood 

 granules are affected by ether, and they dissolve in hot caustic 

 potash little, if at all, more readily than known micrococci, 

 bacilli, and bacillar spores,* but they are not all of them cer- 

 tainly to be understood as of bacterial character. The fatty 

 bodies are the next organs to suffer, after the alimentary canal, 

 and speedily undergo an immense degeneration. 



That this disease is contagious is shown by its unequal dis- 

 tribution in the neighborhoods affected by it ; by its gradual 

 though rapid progression from one part of the field to an- 

 other ; by its evident independence of locality, climate, and 

 weather ; by its apparent progress across the country from east 

 to west ; by the probable success of experiments made to con- 

 vey it from infected regions to others at a distance, not previ- 

 ously invaded by it ; and, finally, by its evident bacterial char- 

 acter. 



In 1883 and 1884, numerous cultures were attempted in 

 beef broth by the strictest methods of fluid culture in tubes 

 arid flasks, the accuracy of which was attested by the fact that 

 the check tubes in every instance remained unchanged through- 

 out. Not all the cultures were successful, several careful 

 infections from the blood especially being without result ; in 

 other cases, however, such infections from the blood of still 

 living larvae yielded the spherical inicrococcus figured in the 

 plate, identical in appearance with that observed in the fluids of 

 the diseased larvae, but larger in average size than the supposed 



* Contrary to the statement frequently made respecting the effects 

 of alkalies upon bacteria, I have found that hot solutions of cau?tic 

 potash rapidly attack both the cells and spores of Bacillus subtilis and 

 the common micrococci of fermentation. Two or three times heating 

 to a boiling point in a strong solution is sufficient in most cases to com- 

 pletely destroy these microbes. 



