9 
cause of American foul brood as found in the scales is not killed by 
heat at 65° C. applied for twenty minutes. 
Up to the present time there is no authentic record of this disease 
having been produced by experimental inoculations of pure cultures. 
Knowing that by the feeding method the disease may be produced, 
pure cultures of Bacillus larve have been mixed with sterile sugar 
sirup and fed to healthy colonies with the result that the disease 
appeared in the colonies within three weeks with symptoms identical 
with those produced by feeding the scales of the disease. In the ropy 
brown mass of the decaying larvee in the disease which is produced 
experimentally by feeding pure cultures of Bacillus larve there are 
found the same large number of spores and rods as when the disease is 
produced by feeding the scales or when the disease is found in an 
aplary. Pure cultures of Bacillus larve have been obtained from the 
larvee dead from the disease produced experimentally by feeding pure 
cultures of Bacillus larve. 
Some European investigators of brood diseases omit the symptoms, 
so that it is impossible to tell which disease they are investigating. 
Their descriptions of microorganisms also are entirely too brief. These 
facts have led to much confusion, and they necessitate much additional 
work on the part of other investigators. They have also added to the 
present confusion. From what can be gained from their papers, the 
author is inclined to believe that Burri has been working with Bacillus 
larve and has been referring to it as the “ bacillus difficult of cultiva- 
tion;’’ that Maassen has been working with Bacillus larve and has 
been referring to it as Bacillus brandenburgiensis, and that von Buttel 
Reepen has referred to Bacillus larve as “‘B. burri.’ It is hoped that 
this confusion may soon cease to exist. 
In the study of Bacillus larve on this new medium some interesting 
additional facts have been observed in the morphology and cultural 
characters of this organism which will be given in a bulletin from this 
Bureau in the near future. One fact is mentioned now because it seems 
to have caused one German investigator, Dr. Albert Maassen, to fall 
into error in the interpretation of certain findings. This fact is that 
this species, Bacillus larvw, produces a large number of giant whips. 
(Giant whips are at present believed to be in some way a modification 
of flagella, the motile organs of bacteria.) These giant whips appear 
in pure cultures of Bacillus larve and persist there for a long time. 
The structures which Maassen evidently saw and reported in two differ- 
ent publications, naming them Spirochwta apis, are nothing other than 
giant whips which normally belong to Bacillus larve and which are 
formed by the growth of Bacillus larve in the larve of the bee. 
Maassen seems to have no further evidence that the structures which 
he saw are spirochetes than what could be gained by a microscopic 
examination of the remains of the dead larvee which had suffered from 
