MISCELLANEOUS NOTES. Id If, 



objects Id their uiituiiil smiouiuliiig.s und thai, tliercforo, there can be uo 

 ([uestion of protective colouration in their case, Tliero seems to be a diversity 

 of opinion on this subject, as shown by C'oh'>nol Burton in his ((notation from 

 Sir Samuel Baker (page 40.>). However, even ailmitting that Mr. Selons is 

 right, it cripples his theory of colouration by environment at least as mnoli. 



This brings me to the weakest point of the environment theory —it fails to 

 give a satisfactory cause for mimicry. ]Mr. Selons attempts to prn[) his case 

 by one reference to those phenomena, but. in rny humble (tpinion, fails 

 entirely to achieve his object. 



He describes a South African butterfly — Precis arlaaia- — which below is 

 coloured in the exact resemblance of a dead leaf, but is bright hned above 

 (apparently a very similar insect to the Indian genus Kalliina). He explains 

 the markings of the undorsurface of the wings by the influence of the dead 

 leaves of the forest floor among which this butterfly settles. This indeed 

 must strike one as far fetched. One might admit that, through some at 

 present still mysterious agency, the environment of dead leaves could in- 

 fluence the butterfly to assume a universal sombre hue, or even a blotched 

 appearance vaguely resembling the colour and shape of a dead leaf, but that 

 it can call into being markings closely copying the venation of a leaf and add a 

 short tail to the hind wing to represent the leaf stalk, is more than the imagin- 

 ation will rise to. 



Then, too, how is one to account for the bright colours of the dorsal aspect 

 of the insect ? Is one to understand that the action of the environment is more 

 or less of a photographic nature and does not act on the upper surface because 

 the wings are usually held applied together, or because they are turned away 

 from the dead leaves V Accepting the influence of environment it seems more 

 reasonable to believe that the effect is through a reaction of ihc whole 

 vital organism and not merely on surfaces exposed. 



Mr. Selous goes on to state that there seems no reason why butterflies in 

 South Africa should be protectively coloured as he has never seen a bird 

 attempt to catch a butterfly, but these insects have other enemies, hzards for 

 instance. 



There are numberless examples of more or less perfect mimicry, some so 

 minutely accurate in every detail as to be absolutely inexplicable except by 

 adaptation for protective purposes working through natural selection. 



And this adaptation must be not merely on the one side but interacting on 

 both — the prey and the preyer. The one becoming more and more perfect 

 for concealment while the other becomes more and more qualified to detect 

 the fraud. 



At least no more plausible, no more convincing hypothesis, indeed no other 

 credible explanation, has as yet been suggested to my knowledge. 



It was Bates, I think, who described an incident of which he was an eye 

 witness in South America, I write from memory and may be incorrect in 

 detail, l)ut the main facts are accurate. 

 31 



