288 THE STRUCTURE AND LIFE OF BIRDS cap. 
nestling, unless very recently hatched, crawls off on 
all fours, making much use of not only his enormous 
feet, but of the great claws that grow at the ends of 
the two first digits of his hand. If you try to pull 
him from the nest by the legs, he holds fast by means 
of these wing-claws and his beak. Often a young 
bird may be found clawing his way onward some 
distance from the nest. If he tumbles into the water 
he proves to be a born swimmer and diver. All ‘this 
is so astonishing that some people are inclined to 
hesitate before they accept it as true. But the paper 
by Mr. J. J. Quelch, from which I derive this account 
of the bird’s habits, is based upon patient and careful 
observation. Nor does the Hoatzin, so far as his 
infant mode of life ‘is concerned, stand absolutely 
alone. The young Ionornis, a Florida bird, has been 
seen to climb out of his nest by means of his wing- 
claws,! and besides this the anatomy of the young 
Hoatzin bears witness to his habits. The wing-digits 
are enormously developed. I have already mentioned 
that the embryo has a distinct rudiment of a fourth. 
More remarkable is the great length of its first. 
Though No. 2 is of wonderful dimensions, yet No. 1 
is more than half its length. And each of these two 
carries at its end avery big-claw. Contrast with them 
the digits of a Swift's wing ; there we find the first 
hardly more than a quarter of the length of the second, 
and there is no sign of a claw on either In the 
1 Shufeldt, /é2s, vol. ii., 1890. 
2 The hand of the embryo Hoatzin is here compared with 
that of an adult Swift. The hand of an embryo Swift would 
probably present a very great, though not so great, a contrast, 
