EUROPEAN FOULBEOOD. 19 



Table V. — Resistance of BaciUun plittoio to dryiny ut refriyerator tetnperature 



Date of inoculation. 



Period of drying. 



Jfontlis. 



Oct. 17, 1915.. 

 Sept. IH, 1916. 

 May .3, 1916... 

 Juno 23, 1910.. 

 May2f), lOlC... 

 June 23, 1910.. 

 Julv31, 1910.. 

 Sept. IS, 1916. 



Days. 

 26 

 28 

 12 

 

 2 

 

 7 

 18 



Results of inoculation. 



European foulhrood produced. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 



From Table II it Avill be observed that Bacillus pluton in a dry 

 film made from the contents of infected larvae resisted drying at 

 incubator temperature for approximately one year. Table III shows 

 that at room temperature, other conditions being similar, the re- 

 sistance is approximately equal to that at incubator temperature. 

 At outdoor temperature, as shown by Table IV, the resistance is 

 again approximately the same. At refrigerator temperature, Table 

 V, the experiments do not include the period at which Bacillus pluton 

 is destroyed. In 10 months the organism was still viable and the 

 results of the inoculations indicate from the character of the infec- 

 tion produced after such a period that at refrigerator temperature 

 Bacillus pluton will remain alive for a longer period than at the 

 other temperatures studied. 



RESISTANCE OF BACILLUS PLUTON WHEN DRY TO DIRECT 



SUNLIGHT 



In experiments relative to the resistance of Bacillus pluton, when 

 dry, to the direct rays of the sun, smears are made of the contents of 

 stomachs of European foulbrood larvae in Petri dishes or on slides, 

 and after becoming dry are exposed to the direct rays of the sun. 

 After intervals reckoned in hours inoculations are made by feeding, 

 using the direct method. Infection resulting from such inoculations 

 shows that the drying has not killed the organism. In Table VI 

 experiments performed in this connection are summarized : 



Table VI.- 



-Ref;tilts of inoculation icith Bacillus pluton in a dry film' exposed to 

 direct sunlight 



Date of inoculations. 



Period 



of 



exposure. 



Results of inoculations. 



July 21, 1914. 

 Sept. 18,1913. 

 July 31, 1914. 

 Sept. 22, 1915. 

 July 21, 1914. 

 Sept. 27, 1915. 

 Aug. 7,1914.. 

 July 21, 1914. 

 Aug. 7,1914.. 

 Sept. 10, 1915: 

 Sept. 25, 1915. 

 July 22, 1914. 

 Sept. 8,1915.. 



Hours. 



European foulbrood produced. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 

 Do. 



