292 REGENERA TION 



highly probable that it will prove true that there are many kinds of 

 adaptive responses that must be considered separately and each on its 

 own merits. Let us, therefore, confine our concluding remarks en- 

 tirely to regenerative changes which, after they have been completed, 

 are for the good of the organisms. Our preceding discussion has led 

 to the conclusion that the phenomena of regeneration are not pro- 

 cesses that have been built up by the accumulation of small advances 

 in a useful direction ; that they cannot be accounted for by the sur- 

 vival of those forms in which the changes take place better than in 

 their fellows, for it is often not a question of life and death whether 

 or not the process takes place, or even a question of leaving more de- 

 scendants. On the contrary, it seems highly probable that the regen- 

 erative process is one of the fundamental attributes of living things, 

 and that we can find no explanation of it as the outcome of the selec- 

 tive agency of the environment. The phenomena of regeneration 

 appear to belong to the general category of growth-phenomena, and 

 as such are characteristic of organisms. Neither regeneration nor 

 growth can be explained, so far as I can see, as the result of the use- 

 fulness of these attributes to the bodies with which they are indisso- 

 lubly associated. The fact that the process of regeneration is useful 

 to the organism cannot be made to account for its existence in the 

 organism. 



