BuLuer.—0n Eudynamis taitensis. 353 
Art. XLIV.— Remarks on the Long-tailed Cuckoo (Eudynamis taitensis). 
By Warrer L. Burzrn, C.M.G., Sc.D. 
[Read before the Wellington Philosophical Society, 3rd August, 1878.] 
Terk is a remarkable phenomenon in the animal world known to naturalists 
as '* mimicry,” or the law of protective resemblance. It is developed chiefly 
among insects, and particularly among the Lepidoptera. Mr. Wallace des- 
cribes, at page 205 of his enchanting book on the ** Malay Archipelago,” a 
butterfly which, when at rest, so closely resembles a dead leaf as almost to 
defy detection. The varied details of colouring combine to produce a disguise 
that so exactly represents a slightly curved or shrivelled leaf as to render 
the butterfly quite safe from the attacks of insectivorous birds, except when 
on the wing. The flight of the species, on the other hand, is so vigorous 
and rapid that it is well able then to protect itself. Mr. Wallace adds that 
in many specimens there occur patches and spots, formed of small black 
dots, so closely resembling the way in which minute fungi grow on leaves, 
that it is impossible not to believe that fungi have grown on the butterflies 
themselves! This protective imitation must obviously favour the species in 
the common struggle for existence, and may of itself be sufficient to save it 
from extinction. But there is another kind of ‘ mimicry” where one 
insect which would, on discovery, be eagerly devoured, assumes for similar 
protective purposes a close resemblance to some other insect notoriously 
distasteful to birds. and reptiles, and often belonging to a totally different 
family or order. Numberless instances might be given in illustration of 
this singular fact, every department furnishing examples of adaptation more 
or less complete, and all being explainable on the principle of variation 
under natural selection or the “survival of the fittest." Mr. Wallace, 
when exploring in the Moluccas, was the first to discover similar instances 
of mimicry among birds, although the law of protective colouring had long 
been observed to exist in-the case of birds’ eggs. He gives two very curious 
examples of external resemblance, co-existing with very important struc- 
tural differences, rendering it impossible to place the model and the copy 
near each other in any natural arrangemeut. In one of these a honey- 
sucker has its colours mimicked by a spevies of oriole, and the reason is 
thus stated ;—** They must derive some advantage from the imitation, and 
as they are certainly weak birds, with small feet and claws, they may 
require it. Now, the Tropidorhynchi are very strong and active birds, 
having powerful grasping claws, and long, curved, sharp beaks. They 
assemble together in groups aud small flocks, and they have a very loud, 
bawling note, which can be heard at a great distance, and serves to collect. 
ald 
