Pflanzenkrankheiten. — Bacteriologie. 623 



It is also different from Bacteriutn phaseoli, although both orga- 

 nisms produce Spotting of bean leaves and pods. 



The name Bacteriuni aptatum, n. sp., is suggested. 



Jongmans. 



Burrill, A. C, Insect control important in checking fire 

 blight. (Phytopathology. V. p. 343—347. Nov. 1915.) 



Referring to Bacillus amylovorus. Trelease. 



Hotson, J. W., Fire blight on cherries. (Phytopathology. V. 

 p. 312-316. pl. 14. Nov. 1915.) 



Referring to Bacillus atnylovorus. Trelease. 



O'Gara, P. J., A Podosporiella disease ofgerminatingwheat. 

 (Phytopathology. V. p. 323—326. pl. 15, 16. Nov. 1915.) 



Ascribed to Podosporiella verticillata sp. nov. . Trelease. 



Ayers, S. H. and W. T. Johnson. Khxlxiy oi Streptococci io 

 survive pasteur iza tion. (Journ. Agric. Research. II. p. 321 — 

 330. 1914.) 



The thermal death points of 139 cultures of Streptococci isolated 

 from cow feces, from the udder and the mouth of the cow, and 

 from milk and cream showed a wide Variation when the heating 

 was performed in milk for 30 minutes under conditions similar to 

 pasteurization. 



The Streptococci from the udder were, on the whole , less 

 resistant and those from milk and cream more resistant to heat 

 than those lYom the mouth of the cow and from cow feces. 



Among the 139 cultures of Streptococci there were 22 that for- 

 med long chains, which, for the purpose of this paper, were con- 

 sidered as typical Streptococci. The others were considered atypical. 

 The typical Streptococci were much less resistant to heat then were 

 the atypical. 



Two classes of Streptococci seem to survive Pasteurization: a) 

 Streptococci which have a low majority thermal death point but 

 among which a few cells are able to survive the Pasteurizing tem- 

 perature. This ability of a few bacteria to withstand the pasteurizing 

 temperature may be due to certain resistant characteristics peculiar 

 to a few cells or may be due to some protective influence in the 

 milk, b) Streptococci which have a high majority death point. When 

 such is the case, the bacteria survive because the majority thermal 

 death point is above the temperature used in pasteurization. This 

 ability to resist destruction by heating is a permanent characteristic 

 of certain strains of Streptococci. 



The thermal death point determinations were made in milk in 

 such a manner as to represent actual conditions of pasteurization 

 by the holder process; therefore the results show what may be 

 expected in commercial pasteurization, and it is evident that some 

 Streptococci may survive the process. Howevcr. different results 

 might have been obtained if a larger number of cultures had been 

 studied and if other methods and media had been used for deter- 

 mining the thermal death points. Jongmans. 



