THE AMERICAN NATURALIST [Vol. XLIV 



variation are classed as fundamental conditions in evolution. 

 Some of these passages will be found on pages 29-34, 59-60, 

 79-80, 138. I also show that the forms of isolation and selec- 

 tion, that divide and guide the process of evolution, are often 

 determined by relations between sections of the species, and 

 may therefore be classed as autonomic. See pp. 138-39, 141-44 

 and 158. These autonomic forms of isolation and selection come 

 under what Dr. Cook defines as processes of evolution, that is 

 "processes of spontaneous change," as does also the process of 

 reproduction with variation. If autonomic processes of isola- 

 tion and selection are forms of evolution, shall we claim that 

 natural selection, because it relates to the power of individuals 

 and groups to meet influences in the environment, has, there- 

 fore, nothing to do with evolution, pxeept as it retards evolution? 

 If the power to assimilate good and abundant food helps in the 

 process of evolution, may not the survival of those having this 

 power in the fullest measure help in the same process? How 

 then can Dr. Cook say, as on the second page of his article, that 

 isolation and selection neither cause evolution, nor help it along ? 

 I can suppose that his answer might be, that, in as far as these 

 factors have influence, the changes produced cease to be spon- 

 taneous, and, therefore cease to be evolution, as he understands 

 evolution. But this explanation does not seem to be applicable 

 to cases of transformation arising under isolation and selection 

 caused by autonomic influences, for example by sexual and so- 

 cial instincts. 



There are. it seems to me, many difficulties in the way of re- 

 garding the term evolution as applicable only to "spontaneous 

 processes of change," unless we class all vital action, including 

 variation and the survival of the fittest, as spontaneous, in that 

 it arises from within, and its origin is life producing life from 

 itself, and never life springing out of the dead environment, or 

 out of widely different forms of life. And then we should have 

 to meet the objection that all life is dependent on external con- 

 ditions for its food, and, therefore, for continued existence, and 

 so no vital action is spontaneous in the sense that it is indepen- 

 dent of conditions in the environment. 



Let us suppose that a little snail, clinging to a leaf is carried 

 by a bird, from the home of the species in a valley on this island 

 of Oahu, and dropped in an adjoining valley half a mile away, 



