358 LETHE E. MOERISON AND FRED W. TAXNER 



The forms isolated from water were Gram positive and in this 

 characteristic, also, agreed with the forms described in the litera- 

 ture. Their destructive nature is indicated by their action on the 

 proteins in milk and on gelatin. Indol and hydrogen sulphide 

 were produced in most media. Rabinowitsch (1895) reported 

 the proteolytic abihties of the thermophiles to be their most 

 characteristic function. 



Although none of the cultures studied fermented any of the 

 sugars used, many of them did produce some acid in glucose or 

 sucrose broth; this together with the fact that all of them showed 

 diastatic action on starch would seem to indicate that these ther- 

 mophiles decompose the more complex carbohydrate molecules 

 more readily than they do the simple sugars. That many of the 

 thermophiles decompose cellulose quite readily is seen in a review 

 of the literature on those types that function in spontaneous 

 heating during the fermentation of malt, tobacco, cotton, hay, 

 and manure, the fermentation of silage and the decomposition of 

 cellulose. 



The fact that some of these cultures came from water from quite 

 deep wells and others from surface waters demonstrates that even 

 in water the thermophiles can exist at widely varjdng ranges of 

 temperature. They are probably widely distributed in waters 

 and had larger portions of the samples of water been used for 

 plating, no doubt, many more cultures would have been isolated 

 from the 224 samples of water examined. The widely differing 

 sources of the thermophiles described in the hterature also indi- 

 cate that they are widely distributed in nature and further investi- 

 gations of their temperature relations will explain this distribu- 

 tion. Rabinowitsch (1895) and some others have claimed that 

 this ability of thermophiles to grow at a high temperature was a 

 property of adaptation to en\ironment. Blau and Bruini both 

 claimed that many non-thermophiles had many of the same 

 characteristics as thermophiles. Other investigators have pub- 

 hshed data to support this claim. Bredfeld (1878) gradually 

 developed the resistance of spores of Bacillus subtilis until it took 

 three hours at 100°C. to kill them or five minutes at 110°C. 

 Koch (1876) observed the germination of spores of Bacillus 



