MELANISM AND MELANOCHROISM. 51 



quotes at length from Mr. A. R.Wallace's recent Address to 

 the Biological Section of the British Association at Glasgow, 

 but the conclusions of Mr. Wallace are more or less open to 

 question, and I doubt altogether, both his conclusions and the 

 one at which Mr. Birchall arrives : — "As it thus appears certain 

 that greater strength of constitution and more powerful anti 

 acute perceptive faculties are, from some yet unknown cause, 

 associated with dark colours in the vertebrata, may we not 

 presume that insects are subject to the same law, and that 

 dark varieties of lepidoptera are able to spread and increase 

 ■ under adverse conditions, whilst the lighter coloured types fail 

 to do so, and are consequently eliminated in the struggle for 

 life, and that the occurrence of melanic forms may be thus 

 reasonably explained as a simple case of the * survival of the 

 fittest ' ? " 



Taking man as the highest of the vertebrata, such a conclu- 

 sion as this seems to force us on the horns of a dilemma. 

 Either the pale Anglo-Saxon race, which has shown its strength 

 over all other races, and has fixed itself as the predominant 

 race of the world, must still be looked upon as inferior to the 

 races under its sway, or we must look upon the predominant 

 race as a great exception to what above is called "the rule," 

 although I do not follow out the application of " the rule." 

 Dr. F. Buchanan White, dealing with this question {Ent. Mo. 

 Mag., vol. xiii., p. 149), writes : — " That melanochroic (or 

 melanic) insects are peculiarly favoured with stronger constitu- 

 tions and more acute senses, there is not, I think, any reason 

 for supposing. Frequently, in fact, melanochroic (and more 

 frequently, melanic) individuals are of smaller size than the 

 typical form." I think decidedly, variation in size in lepidoptera, 

 has its origin essentially in phytophagic causes, and that where 

 melanic forms are small, the size is due to phytophagic, the 

 melanism, to other causes. Mr. S. Radcliff Fetherstonhaugh 

 also discusses Mr. Birchall's conclusion in the same volume of 

 the Ent. Mo. Mag., p. 215, and writes : — " Mr. Birchall quotes 

 from learned writers, who assert as fact that dark coloured 

 animals, from the lower orders up to th6 superior animal, man, 

 have advantages in freedom from disease, less liability to 

 parasites, superior acuteness of the senses, etc., which their 

 paler coloured fellows do not possess ; I must say, I do not 

 see any foundation for this doctrine. In the races of men it 

 certainly does not appear to hold good, as the fair-haired Saxon 

 is able to hold his own physically and intellectually against the 



