354 Transactions.—Zoology. 
a number together in time of danger. They are very plentiful and very 
pugnacious, frequently driving away crows and even hawks, which perch 
on a tree where a few of them are assembled. It is very probable, there- 
fore, that the smaller birds of prey have learnt to respect these birds, and 
leave them alone, and it may thus be a great advantage for the weaker and 
less courageous Mimetas to be mistaken for them. This being the case, 
the laws of Variation and Survival of the fittest, will suffice to explain how 
the resemblance has been brought about, without supposing any voluntary 
action on the part of the birds themselves; and those who have read Mr. 
Darwin's ‘ Origin of Species’ will have no difficulty in comprehending the 
whole process.’ 
Among the many minor instances that have attracted notice, the 
English cuckoo (Cucubus canorus) is supposed to derive protection from the 
resemblance of its markings to those of the sparrow-hawk / Accipiter nisus), 
but the resemblance is far more strikmg between our long-tailed cuckoo 
(Eudynamis taitensis) and a North American species of hawk (Accipiter 
cooperi). In the fine specimens of the former which I exhibit this evening, it 
will be observed that the markings of the plumage are very pronounced, 
while the peculiar form of the bird itself distinguishes it very readily from all 
other New Zealand species. Beyond the general grouping of the colours there 
is nothing to remind us of our own bush-hawk, and that there is no great 
protective resemblance is sufficiently manifest from the fact that our cuckoo 
is persecuted on every possible occasion by the tui, which is timorous enough 
in the presence of a hawk. During a trip, however, on the Continent, in the 
autumn of 1871, I found in the Zoological Museum at Frankfort, what 
appeared to be the accipitrine model, in a very striking likeness to our bird. 
Not only has our cuckoo the general contour of Cooper’s sparrow-hawk, but 
the tear-shaped markings on the under parts and the arrow-head bars on 
the femoral plumes are exactly similar in both. The resemblance is carried 
still further in the beautifully banded tail and marginal wing-coverts, and 
likewise in the distribution of colours and markings on the sides of the neck. 
On turning to Mr. Sharpe’s description of the “young male” of this species 
in his Catalogue of the Accipitres in the British Museum (p. 187), it will be 
seen how many of the terms employed apply equally to our Eudynamis, 
even to the general words “deep brown above with a chocolate gloss, all 
the feathers of the upper surface broadly edged with rufous.” 
The coincident existence of such a remarkable resemblance to a New 
World form, cannot of course be any protection to an inhabitant of New 
Zealand, and I do not pretend in this instance to apply the rule; but in the 
light of natural selection, to which at present no limit can be WA the 
fact itself is a suggestive one, the more so when we remember that this 
BS i a an ota cg A a lO e re 
