20 BULLETIN 810, V. S. DEPARTMENT OF AGRICULTURE. 



Table VI. — Results of inoculation ivith Bacillus pluton, etc. — Continued 



Date of inoculations. 



Sept. 20, 1915 

 Sept. 24,1915 

 Sept. 14,1915 

 Aug. 16,1915. 

 Sept. 14,1915 

 Sept. 13, 1915 

 Sept. 20, 1915 

 Aug. 3,1915.. 

 Sept. 14,1915, 

 Aug. 16,1915. 

 Aug. 23,1915. 

 Sept. 14, 1915. 



Period 



of 



exposure. 



Results of inoculation. 



No disease produced. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 



Observations recorded in Table VI show that Bacillus pluton in a 

 dry film made from the contents of the stomachs of larvae sick or 

 recently dead of European foiilbrood resists the direct rays of the sun 

 for from 21 to 31 hours. 



RESISTANCE OF BACILLUS PLUTON IN WATER TO DIRECT 



SUNLIGHT 



In performing the experiments relative to the effect of direct sun- 

 light on Bacillus pluton suspended in water, an aqueous suspension 

 of the contents of stomachs of infected larvae is exposed, in a Petri 

 dish with the top removed, to the direct rays of the sun. After in- 

 tervals reckoned in hours inoculations of healthy larvae are made to 

 determine whether the organisin is viable. The direct method is 

 used. Experiments made in this connection are summarized in 

 Table VII: 



Table VII. — Resistance of Bacillus pluton suspended in water exposed to the 



direct rays of the sun 



Date of inoculation. 



1915. 

 Aug. 24 



Do , 



Aug. 16 



Aug.8 



Aug.9 



Aug.16 



Aug. 24 



Sept. 13 



Aug. 18 



Aug.16 



Sept.l4 



Aug. 17 



Aug. 20 



Sept. 14 



Do 



Do 



July 28 



Aug. 20 



Results of inoculation. 



European foulbrood produced. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 

 No disease produced. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 



Table VII shows that Bacillus pluton, when suspended in water 

 and exposed to the direct rays of the sun, was destroyed in from 

 5 to 6 hours. 



