2; t Mr. G. E. II. Barrett- Hamilton on 



Avhicli ill allied forms arc already white have this colour 

 " !«tiU purer and more dazzling in the Kamtschatkan forms/' 

 while " the other colours seem to be purer, and, in many 

 instances, at least, to be more intense also." The colour 

 which seems to suffer the most reduction is black, but that 

 is only as re<;ards intensity. 



Arguing from the facts that the peculiar Kamchatkan 

 forms are considerably whiter than those of any other part 

 of Siberia, that the climate of Kamchatka is less severe 

 than that of Siberia generally, and that the white forms are 

 not Arctic, being found so far south as 53° north latitude, 

 Dr. Sfejneger believes that the " theory of climatic conditions 

 producing the geographical subspecies, races, or whatever 

 they may be styled, does not hold good, at least as far as the 

 increase of the white colour at the cost of the others, 

 especially of black, is concerned." 



The facts, as observed in connection with the peculiar 

 Kamchatkan birds, do not, he thinks, bear out the 

 conclusions deduced from observations made " long ago, as 

 far back as Gloger's earliest days," that since "the Siberian 

 ornis generally showed a tendency towards an increase of the 

 white colour," and " a similar tendency seemed to obtain in 

 forms living nearer the Arctic," consequently " the white 

 colour was due to the increased cold." 



There are so many, as it seems, clear instances of the 

 parallel tendency of the mammals and birds of a whole 

 region or district to vary in a particular direction, either 

 under the influence of Natural Selection or of the direct 

 stimulus of the weather and environment, but, in any case, 

 to suit the particular climatic conditions to which they are 

 exposed, that ] should be loth to think that Dr. Stejtieger 

 is right here, and 1 feel bound to search for some other 

 explanation of so striking a case of parallel variation — some 

 explanation which shall be compatible with the idea of 

 climatic influence. It is important to remember that such 

 phenomena as those which Dr. Stejneger describes can only 

 be said to owe their existence to the influence of climate in 

 so far as such influence docs not conflict with or run counter 



