78 Causes and Course of Organic Evolution 



since in analytic processes the higher may constantly become 

 degraded into lower phases. Equally true is this for such 

 inorganic bodies as a colloid or crystalloid solution, or a bar 

 of iron. 



During the past quarter century increasing attention has 

 been given to the phenomena of surface tension, as exhibited 

 between substances of different chemical composition. Thus, 

 since Butschli, Berthold, and Quincke explained the streaming 

 movements of cell protoplasm as being fundamentally due 

 to surface tension between the protoplasm and enclosed sap, 

 other writers have tried to extend this inter-relation between 

 many organic compounds. But surface tension and the internal 

 changes in substances that are due thereto do not represent a 

 type or species of energy traversing such substances. They 

 merely indicate the relative rapidity wath which a definite 

 energy or energies are working to effect molecular changes in 

 diverse substances, when the molecules of these are brought 

 within suitable fields of interaction. The high surface ten- 

 sion, therefore, th-it may be demonstrated to occur between 

 different organic bodies, or between these and surrounding fluids, 

 would be due to the complex character of the molecules, and 

 correspondingly to the high discharges of electric, biotic, or other 

 forms of energy set free during the process of interaction. 



In the last chapter we showed that the Acaryota are wholly 

 or largely protoplasmic, and that only in highest genera of the 

 group a diffuse nucleo-protein body was observed. Such 

 simple organisms should aid us then by yielding simple material. 

 But it was also stated that, even in the highest plants and 

 animals, at least temporary life-phases might be passed through 

 when only protoplasmic activity — and that usually sluggish — 

 might be traced. In the past fifteen years, however, the view 

 has been widely held by biologists that nuclear material is 

 essential for most life processes. But consideration alone of 

 the Acaryota would suggest that in the lowest or most sluggish 

 life actions nuclear material may be entirely dispensed with. 



As a first example of energy distribution we may now examine 

 Beggiatoa alba, one of the common sulphur bacteria. Living 



