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able. But there can be no dispute as to the high import- 

 ance and interest of the facts that he has brought together, 

 and I trust that the examples I have given may induce 

 entomologists who are interested in the study of evolution, 

 and by whom these researches may hitherto have been over- 

 looked, to make themselves acquainted with this mine of 

 valuable information. They may not find themselves able to 

 agree with the author at all points, but they will be intro- 

 duced to a great mass of material with an important bearing 

 on the nature and causes of variation, the working of 

 heredity, the efficacy of selection, the significance of warning 

 colours, and many other matters essential to a proper 

 comprehension of the problem of evolution. 



There is one other phase of this great problem about which 

 I should like to say a few words, because here again our 

 special entomological studies have an important part to play. 

 They have already conti-ibuted much towards the comprehen- 

 sion of this side of the question, and I am convinced that they 

 are capable of leading to a still further advancement of know- 

 ledge in the same direction. I refer to the psychic aspect of 

 evolution. 



It was fully recognised by Darwin himself that mental no 

 less than physical characters are subject to evolution. The 

 same principle was adopted by Wallace, not, it is true, with- 

 out reservation, and received at his hands some interesting 

 developments. But to Professor Mark Baldwin belongs the 

 principal credit of insisting on and driving home the fact that 

 evolution is psychophysical ; that, as he puts it, "there are not 

 two evolutions, one ' organic ' and the other ' mental/ but that 

 mind and body have evolved by one process and in one series 

 of graduated stages." Now in order to illustrate in a forcible 

 manner the interdependence of physical and psychic pheno- 

 mena in evolution, he has recourse to the theory of warning 

 colours in insects. This he expands in the following manner : 

 "As preliminary to the theory there is the fact of coloration, 

 which is distinctly physical. The question is as to its origin. 

 The theory holds it to be due to the warning given to other 

 individuals that a particular colouring is distasteful or 

 poisonous. Now in order that this warning be given, the 



