474 DISEASES OP BEES. 



its effects mainly by the dying of the brood, the contagion 

 being transmitted through the food of the larvae.' 



787. Dr. G. F. White, of the Bureau of Animal Industry 

 at Washington, has lately described two kinds of foul brood, 

 which he denominates "bacillus pluton," until lately popularly 

 and commonly called "black brood," and "bacillus larvae," 

 the more malignant kind, which is not so easily produced in 

 cultures by bacteriologists, since Mr. White was unable to 

 produce it in the common cultures, a bouillon made of bee- 

 larvae being necessary. The first he denominates "European 

 foul-brood" because it was first described in Europe, the second 

 "American foul-brood" because it was first described by him- 

 self in America, but both kinds evidently exist in either hemis- 

 sphere. The name "bacillus"! means "a stick" and is applied 

 to both diseases because the germs of the disease are imper- 

 ceptible sticks which break successively into several parts, 

 every one of which forms a colony of spores, that pass through 

 divers shapes before developing into new bacilli. We can 

 judge of the promptness of their reproduction, and of their 

 minuteness, when we read in Cheshire, that a dead larva fre- 

 quently contains as many as one billion of these spores. (28.) 



788. Bacillus pluton, perhaps the "bacillus alvei" of Cheshire 

 being the lesser of the two diseases will be described first. 

 It has been quite fully mentioned by Dr. PhilUps, in Circular 

 No. 79 of the Bureau of Entomology, to which we refer the 

 student. This disease has been quite prevalent in the United 

 States since 1900. 



DESCRIPTION OF BACILLUS PLUTON. 



The brood dies a little earlier than in the American foul- 

 brood, a comparatively small percentage of it being ever 

 capped, the diseased larvae which are covered having sunken 

 or perforated cappings. A small yellow spot near the head 

 of the larva is the first sign, at death it turns yellow, then 

 black. Some of the dead and dried larvae are removed by 



^Bacillus, plural bacilli, from the Latin, a sHck. 



