24 



BULLETIN 810, U. S. DEPARTMEiNT OF AGRICULTURE. 



each Tvith the contents of a single flask. A summary of the experi- 

 ments is contained in Table XIII : 



Table XIII. — Resistance of Bacillus plnton in honei/ at room temperature 



Date of inoculation. 



Period in honey. 



Results of inoculation. 



Months. 



May 22, 1915... 

 June 12,1915... 

 July 23,1915... 

 June 25, 1915... 

 Aug. 23, 1915... 

 Aug. 3, 1915.... 

 July 12, 1915... 

 Aug. 23, 1915... 

 Sept. 10, 1915... 

 Aug. 16, 1916... 

 May 19,1916... 



May 4, 1915 



June 7, 1913.... 

 June 13, 1913... 

 May 13, 1915... 

 May 14, 1915... 

 May 22, 1915... 

 May 24, 1915... 

 July 31, 1916... 

 May 15,1916... 



Days. 



European foulbrood produced. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 

 No disease produced. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Experimental evidence recorded in Table XIII shows that the 

 virus of European foulbrood when suspended in honey at room tem- 

 perature ceased to be virulent in from 3 to 7 months. 



VIABILITY OF BACILLUS PLUTON IN POLLEN 



Preliminary experiments were made to determine the viability of 

 Bacillus pluton in pollen. Pollen is removed from brood-comb, and 

 an aqueous suspension of the organism obtained from the stomachs 

 of larvae sick or recently dead of the disease is added to it until a, 

 moderately thick, pastelike mass is obtained. This is distributed in 

 Petri dishes and allowed to stand at room and refrigerator tempera- 

 tures, respectively. After different intervals of time the contents of 

 a single dish, after being suspended in water, are added to about 

 300 c. c. of sirup and the suspension is fed to a colony, using the 

 indirect method. The results show that Bacillus pluton was viru- 

 lent after 7 months at room temperature and for more than 10 

 months in the refrigerator. The maximum period during which the 

 organism will remain alive in these two environments has not been 

 determined. 



RESISTANCE OF BACILLUS PLUTON TO CARBOLIC ACID 



Preliminary experiments were made to determine the effect of 

 carbolic acid on the virus of European foulbrood. An aqueous sus- 

 pension of the contents of the stomachs of larvae sick or dead of the 

 disease is first made. A measured quantity of this suspension is 

 added to an equal quantity of an aqueous suspension of carbolic acid 



