208 A NATURALIST IN BORNEO 



whilst a great many philosophic zoologists are sorry 

 failures when it comes to observing the living animal 

 in its natural surroundings. The collector is far too 

 prone to kill at sight every animal he captures; he is 

 usually a bird of passage, and has not the time to 

 devote to the patient and difficult observation of an 

 animal's behaviour and habits of life ; even if he does 

 observe a few facts here and there, his observations 

 are either too incomplete to be of much value, or he 

 does not see their bearing on current theories, and 

 therefore keeps them hidden from the light of day in 

 his private journal. 



Scores of collectors will tell you that they have never 

 seen a bird eat a butterfly ; but if you ask these men 

 what insects they have seen eaten by birds, they are 

 completely nonplussed, and are fain to confess that 

 they have rarely, if ever, seen an insectivorous bird 

 feed at all. As a matter of fact, Mr. G. A. K. Mar- 

 shall most philosophical and competent of field-natur- 

 alists has collected from a variety of sources abundant 

 evidence to show that all manner of birds do prey on 

 butterflies. It is difficult to see how mimicry, amongst 

 butterflies and moths at any rate, could have been 

 brought about except through the agency of winged 

 enemies : in other words, mimicry is brought about by 

 natural selection, and the mimicry hypothesis may be 

 regarded as a corollary of the Darwinian hypothesis ; 

 they must sink or swim together. 



The objections to the mimetic theory, when ana- 

 lysed, are not very serious, and it is significant that no 

 rival theory has yet proved capable of accounting satis- 

 factorily for these remarkable resemblances that exist 

 between animals widely separated in classificatory 



