RELATION OF PLANT PROTOPLASM TO ENVIRONMENT. 261 



small or appear to be absent in active cells; diverse food granules may be seen 

 in the protoplasm; while in regard to a nucleus we would favor the view of most 

 bacteriologists, that such is absent or only represented by minute chromatin 

 granules ("chromidia" of authors) that may be loosely linked together in the 

 substance of the protoplasm. 



In studying the environmental relation of the group from the standpoint of 

 protoplasmic adaptability, it may well be said that during the past 10 years few 

 lines of experimental observation have produced so varied and suggestive results 

 as those dealing with the thermophilic bacteria. Their presence in hot springs 

 had been demonstrated almost a quarter century ago, but their existence in 

 unlimited quantity in soils, in fermenting vegetable refuse, in manure, in the 

 cloaca and alimentary canal of vertebrates, as well as on many living exposed 

 plant parts, had not been suspected. As repeated experiment has shown, these 

 thermo-bacteria are nearly all active at an optimum temperature of 55°-65° C, 

 they are sluggishly — though sometimes actively — vegetating at 70°-75° C, 

 while their spores can in most cases retain vitality at much higher temperatures. 



But more than ordinary interest attaches, in our present inquiry, to the bac- 

 teria that flourish in siliceous, in calcareous, or in sulphur springs. Setchell (9) 

 concluded after study of many western American localities, that "the chloro- 

 phylless Schizomycetes (or bacterial forms) endure the highest temperatures 

 observed for living organisms, being abundant at 70°-71° C, and being found 

 in some considerable quantity at 82° C. and at 89° C." He states also that 

 in siliceous waters the limit of life for active bacteria is 89° C, but in calcareous 

 waters the limit is 71° C. 



About eight years before publication of SetchelTs results, however, Kar- 



linski (10) studied the waters of the hot sulphur springs of Ilidze in Bosnia. In 



the early part of his paper, he gives a table showing the composition of the water, 



and which the writer subjoins for comparison with those already given. One 



of the two springs that yield the supply has a temperature of 58° C, the other 

 of 51° C. 



Sulphate of potash 0.344 Bicarbonate of magnesia 4.547 



bu phate of soda 8.191 Bicarbonate of iron 0.077 



sulphate of strontium 0.030 Oxide of alumina 0.012 



0.485 



Borate of soda 0.053 Silica 



Lh onde of sodium 0.144 Hydrogen sulphide 0.039 



Uilonde of calcium 5.100 Free C0 2 4 - 496 



Hyposulphite of calcium 0.019 - Lithium, manganese, ammonia traces 



phosphate of calcium 0.013 Organic substance 0.152 



bicarbonate of calcium 10.666 Insoluble constituents 24.990 



He accordingly draws attention to the special abundance of sulphate of soda, 

 of the two chlorides, of bicarbonate of lime, and of free C0 2 . But in contrast to 

 those already tabulated in this paper, the writer would emphasize the presence 

 of iron and of phosphorus compounds. 



In the Ilidze waters Zalinski found two thermophilic species. One was 

 named Bacterium ludurigii, the optimum temperature for which was 55°-57° C. ; 



