20 BULLETIN 810, V. S. DEPAETMEKT OF AGEICULTXJEE. 



Table \1. — Results of inoculation icith Banlliis pluton, etc. — Continued 



Date of inoculations. 



Sept. 20, 1915. 

 Sept. 24, 1916. 

 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. 



Observations lecorcled 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 foulbrood 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 organism 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. 



Results of Inoculation. 



1915. 

 Aug. 24 



Do 



Aug. 16 



Aug.8 



Aug. 9 



Aug. 16 



Aug. 24 



Sept. 13 



Aug. 18 



Aug. 16 



Sept.14 



Aug. 17 



Aug. 20 



Sept.l4 



Do 



Do 



July 28 



Aug. 20 



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 

 6 to 6 hours. 



