RELATION OF PLANT PROTOPLASM TO ENVIRONMENT. 2G3 



almost identical with many of the thermophilic Schizophy 



These again 



show every type of gradation in cell structure and in life cycle to the genera of 



the Leptothrice 



that are mainly saprophyt 



parasitic. They again lead 



by Streptothrix , Mycobacterium and others to genera of the Spirilleae on the one 

 hand, and to the larger forms of Bacillus and Bacterium on the other. Whether 

 the group of the Coccaceae should be viewed as a direct offshoot from simpl 



spherical Schizophy 



or as condensed and rounded derivatives from Bac 



terium is a question that need not concern us at present. The important 

 announcement just made by Drew (17) " relates to the role of certain bacteria in 

 depriving surface sea water of nitrogen and in precipitating the vast deposits of 

 chalky mud (oolite) of the Florida-Bahama region. " This is but another proof 

 of the geologic activity of the Schizomycetes, though it is of immense value as 

 carrying such activity into the ocean, and of possibly explaining to us the origin 

 of the great marine chalk and lime beds of former epochs. 



It is regrettable that our knowledge is still very limited as to the bacteria of 



siliceous and calcareous springs. But accepting their 



gnized occurrence 



there, and the great abundance of sulphur bacteria in hot sulphur springs, the 

 conclusion seems fully warranted that hot-spring schizophytic organisms — alike 

 in their schizophyceous and schizomycetous sections — were the primitive organ- 

 isms of the world, and that amid all the environmental changes of denudation, 

 upheaval, cooling, and more recent sharp action of such often severe environ- 

 mental agents as hot suns, hot and cold winds, ice action, etc., some species have 

 survived practically unaltered, from very ancient time amid primitive thermal 

 waters, while hundreds of species derived from these have adapted themselves to 

 a wide range of environmental habitat. 



Naturally, we would regard the algoid or schizophyceous series as the primi- 

 tive and main stock, since they are chemically autotrophic. The saprophytic 

 and parasitic derivatives are in all likelihood offshoots from these. But it must 

 here be borne in mind that though Winogradsky's and Molisch's views differ 

 somewhat as to details of nutrition of the sulphur bacteria, these plants may indi- 

 cate a capacity for autotrophic nutrition, or at least for chemical elaboration and 

 energy-storage, that might give them a synthesizing dignity and independence 

 apart from the Schizophyceae. 



For the Schizomycetes then, as for the Schizophyceae, it is true that many 

 species have become adapted to cool surroundings, and can even continue 



grow and multiply at or below the freezing point 



But it is as true for their 



spores as for the seeds of flowering plants, that after continued exposure to 

 temperatures of - 70° C. to - 100° C. many still survive. So direct experimental 

 and observational evidence both lead us to believe that rich and dense plant 

 protoplasm had from earliest time an adaptive capacity up to at least 100° C 

 and also that it had or in time acquired a life-adaptation to 



Such a w 



100° c 



de range of temperature adaptability would aid many species to 



that otherwise would have succumbed 



