G22 DE. ST, GEOEGE MIVAET OxV SOME LOEIES. 



The blue coloration of both these species, tlie white throat of 

 C. taitianus, and the white spots on G. ultramarinus cannot be 

 " recognition marks." Neither is it to me conceivable that the 

 environment as existing in the Society, Marquesas, and Caroline 

 islands can have educed the blue colour of the two species of 

 Coripliilus or the red colour of Eos rubiginosa. Would it be 

 reasonable to suppose that these varieties in coloration are corre- 

 lated with other unknown useful characters ? Surely if not only 

 the utility, but even the very existence also, of such hypothetical 

 characters are as yet devoid of even a fragment of evidence, 

 positive belief in siicb correlation can only be due to a sort 

 of groundless, irrational " faith " ! 



And here I may be permitted to add a few words in self-defence, 

 since I have recently learned (from private conversation), to my 

 astonishment, that my biological views and arguments have, 

 by some persons, been supposed to be due to a desire on my part 

 to promote views with which physical science has no connexion. 

 Any such purpose I repudiate with all the energy of which I am 

 capable, and I seize this occasion to express my true meaning : 

 When I urge, as 1 do now, that the instances which Captain 

 Hutton and I have brought forward are fatal to a utilitarian ex- 

 planation of the origin of all specific characters (or, indeed, of any, 

 because falsiis in uno falsus in omnibus)^ I none the less unhesi- 

 tatingly and unequivocally affirm they are (as a matter of course) 

 due to natural, biological causes. I know no causes in nature but 

 natural causes, but not all natural causes are mechanical ones. 



My objection to this dogmatic assertion, that the latter, as the 

 exclusive causes, are to be, in all cases, accepted on a priori 

 grounds (as it has been affirmed they should be accepted *), is 

 due even more to what seems to me to be the intellectual 

 limitations of such a view than to its inadequacy. 



After nearly forty years' meditation and examination of the 

 subject, I remain convinced that the cause of specific characters 

 still remains an unsolved enigma. I hope and believe that its 

 solution will nevertheless one day be achieved, but I do not 

 consider it will be so achieved until the higher psychological 

 probleus of Biology have become much more widely understood, 

 and tl.e light thus gained has been reflected on questions of 

 ordinary physiology. 



* A. E. Wallace, Joum. Lina. Soc, Zool. xxv. p. 481. 



