CH. XIV.] LIFE AND MIND. 89 



stitutes the psychical life is all in all, and the processes of 

 physical life come to be regarded as entirely subordinate 

 to the maintenance of this higher correspondence. 



Let us now briefly trace the various extensions and com- 

 plications of the correspondence as it becomes more hetero- 

 geneous, definite, and coherent. Scanty justice can here be 

 done to the subject, since it is necessary for me to compress 

 into half-a-dozen pages the substance of a series of illus- 

 trations, which in Mr. Spencer's exceedingly condensed 

 exposition fill a hundred pages. Nevertheless a few striking 

 facts may be noted down, which will serve to assist in the 

 comprehension of the process. Let us first note that in the 

 simplest forms of life the correspondence extends " only to 

 external relations which have one or both terms in contact 

 with the organism. The processes going on in the yeast- 

 plant cease unless its cell-wall is bathed by the saccharine 

 and other matters on whose affinities they depend. . . . And 

 80 too among the lowest animals, the substances to be 

 assimilated must come in collision with the organism before 

 a,ny correspondence between inner and outer changes is 

 shown." The correspondence is similarly limited in time. 

 The tree, which puts forth its leaves from year to year, does 

 so only in response to luminous and thermal changes which 

 occur contemporaneously. The polyp's tentacles contract 

 only in response to immediately present stimuli. " Alike in all 

 these forms of life, there is an absence of that correspondence 

 between internal relations and distant external relations " — 

 in space and time — which we see exhibited in higher forms. 



Now the extension of the* correspondence in space is 

 effected by the gradual differentiation of organs of sense. 

 One of the most notable achievements of modern biology is 

 the discovery — due among others, to Huschke, Eemak. 

 Milne-Edwards, and Huxley — that all the sense-organs are 

 but successive modifications of tactile structures, or rather, 

 of those simple dermal structures which in the higher 



