BIONOMICS 195 



component molecules. Whence it is to be inferred than any three of 

 these remaining constant, the molecular mobility will vary as the fourth. 

 Other things equal, therefore, the molecular mobility of atoms must 

 decrease as their masses increase ; and so there must result that general 

 progression we have traced, from the high molecular mobility of the 

 uncombined organic elements, to the low molecular mobility of those 

 large-atomed substances into which they are ultimately compounded. 



Applying to atoms the mechanical law which holds of masses, that 

 since inertia and gravity increase as the cubes of the dimensions while 

 cohesion increases as their squares, the self-sustaining power of a body 

 becomes relatively smaller as its bulk becomes greater; it might be 

 argued that these large, aggregate atoms which constitute organic 

 substance, are mechanically weak are less able than simpler atoms to 

 bear, without alteration, the forces falling on them. The very massive- 

 ness which renders them less mobile, enables the physical forces acting 

 on them more readily to change the relative positions of their component 

 atoms ; and so to produce what we know as re-arrangements and decom- 

 positions. 



It is clear that these conclusions (avowedly very tentative) 

 are yet but partial biological interpretations, although, as the 

 study of surface-tension has startlingly revealed, they contain 

 important elements of truth. First of all, terms like 

 "polarity," and particularly "mutual" polarities, take too 

 much for granted. The user of these terms may pretend to be 

 supplying a purely mechanistic interpretation of biological 

 facts, but in reality by tacit implication he is raising the 

 mechanism to the body. It remains to be seen in each case 

 how much of character, of personality, and of work such terms 

 take for granted. In my view every "polarity," like every 

 integration depends primarily on work, and polarity is nothing 

 but bio-dynamic character. Failing this recognition, 

 " polarity " has to this day remained a mysterious concept a 

 mere word, convenient as a cloak of ignorance or a symbol for 

 the unknown which makes the equation possible to state. It 

 only generalises the problem instead of solving it, as we can 

 see from the following definitions : 



Sir E. Ray Lankester states (Daily Telegraph, 16/6/13) 

 that "the real determining ultimate cause of form is in each 

 case, in each living thing, the immense and special heritage 



o 2 



