6oo 



THE BEGINNINGS OF LIFE. 



which subsequently modify the forms and structures of 

 Organisms in the following table : 



Primarily 

 determined by 



CRYSTALS - - - Polarity. 



Subsequently modified by 



Nature of 

 forms affected. 



aM 



1 



! ORGANISMS - - - Polarity * 

 1 (Ephemeromorphs). 



Species. 



* This word is used in the sense in which it is employed by Mr. Spencer, who says : ' If we 

 accept the word polarity as a name for the force by which inorganic units are aggregated into 

 a form peculiar to them, we may apply this name to the analogous force displayed by organic 

 units. But as above admitted, polarity as ascribed to atoms is but a name for something of 

 which we are ignorant ... we simply substitute the term " polarity" for the circuitous expression, 

 " the power which certain units have of arranging themselves into a special form." ' (' Principles 

 of Biology,' 1864, vol. i. p. 181.) 



It should not be forgotten, moreover, that Natural 

 Selection in its most general sense has reference to that 

 co-ordinating power in Nature whereby the fittest of 

 all organisms, of whatsoever kind and howsoever pro- 

 duced, tend to be perpetuated ; whilst Natural Selection 

 in its more special sense is an agency which Mr. Darwin 

 has shown to be capable of c producing fitness between 

 organisms and their circumstances' by perpetuating 

 and intensifying any minute variations of a favourable 

 nature *. The latter is, however, only one amongst other 

 agencies which are capable of giving rise to specific 

 transmutations, although Mr. Darwin often speaks of 

 1 See P . 573. 



