RATIONALISM AND PSYCHOLOGY z^i 



"In spite of these criticisms I am compelled by the re- 

 sults of my investigations to admit that I now believe 

 Prof. Newton's theory to be, in the main, correct "} 



If hermit crabs, to which I have already alluded, 

 now supply instances of an hereditary instinct converted 

 into an absolute necessity, their enemies supply reasoning 

 in adapting their habits towards them ; for it has been 

 noticed that a very young octopus will at once seize a 

 hermit crab; but as the latter had fixed stinging zoo- 

 phytes over the shell [by reason], the octopus recoiled 

 and let its prey escape. Subsequently it was observed 

 to avoid hermit crabs. But older animals of the same 

 species managed cleverly to pull the crab out of its house 

 without being stung.- 



If the acquiring of any habits come under what Mr. 

 Reid calls " psychological change," i.e., from a previous 

 state, when no such habit existed ; and the habit in this 

 case probably arose from the direct, conscious adaptation 

 of means to ends ; then, such are obviously inherited, and 

 the fact that these habits run in direct descent of par- 

 ticular genera or species is an additional evidence that 

 they have become fixed, automatic traits in the race in 

 question. Hermit crabs now have the instinct to go 

 searching for " houses to let ". 



Let us take another example. 



Soles, as fry, are, like other fishes, bilaterally sym- 

 metrical ; but they soon assume the generic habit of 

 lying flat on the ground more or less embedding them- 

 selves in the shingle. The bodily form changes in con- 

 formity with this changed and acquired habit ; as the 

 form of the fry indicates the ancestral type. 



Their present habit suggests the primary purpose of 



^Biomctrika, i., p. i66. 

 2 Stout's Manual of Psychology, p. 257. 

 16 



