208 THE GENESIS OF SPECIES. [CHAP. 



atoms of a salt, there dwells the intrinsic aptitude to 

 crystallize in a particular way. It seems difficult to con- 

 ceive that this can be so; but we see it is so." .... "For 

 this property there is no fit term. 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 word to the analogous force displayed by 

 organic units." 1 



Dr. Jeffries Wyman, 2 in his paper on the " Symmetry 

 and Homology of Limbs," has a distinct chapter on the 

 ' Analogy between Symmetry and Polarity," illustrating it 

 by the effects of magnets on " particles in a polar condition." 



Mr. J. J. Murphy, after noticing 3 the power which crystals 

 have to repair injuries inflicted on them and the modifica- 

 tions they undergo through the influence of the medium in 

 which they may be formed, goes on to say : 4 "It needs no 

 proof that in the case of spheres and crystals the forms 

 and the structures are the effect, and not the cause, of the 

 formative principles. Attraction, whether gravitative or 



1 Mr. Spencer, in an appendix to the first volume of the " Principles of 

 Biology," has explained more fully what he means by the word "innate." 

 He attributes "innate tendencies" entirely to the inherited structures of 

 the "physiological units" produced in them by the total forces of the 

 organisms through which they have been transmitted during the serial 

 evolution of such organisms. This, however, is a mere moving of the diffi- 

 culty a step backwards ; and he by no means gets rid of (what never can 

 be got rid of) the conception of innate power of force proceeding from the 

 organism as distinguished from force proceeding towards the organism. At 

 the very least, Mr. Spencer must attribute to his ultimate units an innate 

 power of inheriting effects of ancestral modifications, and this is, in prin- 

 ciple, a power fully as mysterious as any for which the author of this 

 book here contends. 



2 See the "Proceedings of the Boston Society of Natural History," 

 vol. xi. June 5, 1867. 



3 "Habit and Intelligence," vol. i. p. 75. 4 Ibid. p. 112. 



