BIONOMICS 197 



anderes ausgeiibt werden konnen, in Betracht kommen " 

 (the living cells not only minister to the flow of nutrition, but 

 also transmit other stimulations as between organs and organs). 



External forces such as gravity are, as he says (p. 220), 

 "fur die Polaritat von untergeordneter Bedeutung" (of little 

 importance in polarity). Again, we see that the only remain- 

 ing factors that can thus be seen as of importance are the bio- 

 economic (symbiotic) factors. 



Goebel shows (p. 230) that if any part of a plant receives 

 a "lebhaftere Stoffwanderung " (i.e., as I would say, if any 

 part is the recipient of a prominent share of nutrition by way 

 of remuneration in virtue of the prominence and importance of 

 its function), the polarity of that part is " scharfer 

 ausgepragt," i.e., is more marked and more thoroughly 

 established. 



A polarity thus well established (like a good steady 

 character) is not so easily interfered with as one that is less 

 significant. A disturbing factor always consists in a 

 "Verarmung an Baumaterial " (p. 234) an impoverishment 

 of building material. 



Amongst the lower forms of plants, e.g., Marchantia and 

 Liverworts, Goebel notes the strange fact that "andere 

 Thallusteile anders ' polarisiert ' erscheinen als der vegetative, 

 unbegrenzt weiter wachsende Thallus," i.e., that exaggerated 

 vegetative growth is connected with quite a different polarity 

 from that in more normal growth. We have seen that such 

 exaggerations are attended by a diminution in the output of 

 work, and are generally caused by a surfeiting nutrition, and 

 again we must conclude that our bio-economic explanation is 

 calculated to throw light on " das noch recht dunkle Gebiet 

 der Polaritat" (the yet very dark region of polarity). 



To return now to Spencer: It is true that " the molecular 

 mobility of atoms must decrease as their masses increase"; 

 but whether a large-atomed compound is sufficiently mobile 

 and efficient in its work the point that really matters 

 depends less on mechanical than on " personal " factors. 



