Bui. 1, new series, Div. of Entomology, U. S. Dept. of Agriculture. 



PLATE XI, 



. 2 34700, 



BACILLUS ALVEI (Cheshire). 



[Drawn from nature by Frank R. Cheshire for Jour. R. Micr. Soc., and here reduced one- 

 sixth from the original plate.] 



FIG. 1 . Residue of larva three days dead of bacillus alvei; 6, bacilli. Spores and degener- 

 ated trachae cover the field. 



FIG. 2. Healthy juices of bee larva. 



FIG. 3. Juices of larva (living) with disease in acute stage; a a, leptothrix forms. 



FIG 4. Brood cells from a diseased colony; a a, cells containing healthy pupse; 6 6, 

 sunken and punctured cells in which pupae have died. 



FIG. 5. Cultivation in sterilized agar-agar showing the colony form of bacillus. 



FIG. 6. Same cultivation twenty-four hours later. 



FIG. 7. Spore changing into bacilli. 



FIG. 8. Bacillus passing into spore condition. 



