150 
ON THE CLASSIFICATION OP BIRDS. 
union of the three anterior toes, by producing consider- 
able breadth of sole, gives an unusual degree of steadiness 
to the bird highly conducive to its remaining very long 
in one position. Thus we see that the foot of the king- 
fisher, which at first appears so very imperfect, and so 
totally useless for ordinary purposes, is that which is 
most of all suited to the habits and the wants of the 
bird. The bee-eaters, like the swallows, feed upon the 
yet, unlike those birds, they never perch upon the 
ground ; at least, we can affirm this of the Kuropean 
species {Merops apiaster), which visits the island of Sicily 
every year in great numbers, and remains for near a 
month on its passage from Africa to middle and southern 
Europe. During this period we have sought for many 
years every opportunity of detecting these birds in their 
renthvj position, but never were successful in finding 
them otherwise than on the tops of the olive trees, 
where they rest immoveable, until they again dart off 
for another long excursion. It is indeed obvious that 
they could not walk, for their feet (d) are much the 
same as those of the wood kingfishers {Daceln, fig. 80 . e), 
with this only difference, that the three anterior toes 
are divided tlie whole length of their last joint, the 
scales being rather more conspicuous. 
(129.) ITe shall here notice the foot of the genus 
Bucarns, not as an example of the true syndactyle form, 
but rather to show the wide difference in its construction 
from that of the kingfisher. The species before us is 
that generally called the Buceron naftufns. The general 
structure of the leg, although somewhat short, is strong 
and robust ; the tarsus is nearly twice the length of 
the hind toe, which is shorter than any of the others ■ 
the middle toe is connected to the outer only as far as 
its first joint, the inner being entirely free, or cleft to 
its base ; the claws are stout, and the scales thick and 
strong. The great breadth of the sole, as well as the 
partial union of the toes, clearly shows this bird habitu- 
ally lives among trees, and yet the strength of the foot, 
length of the tarsus, its claws, &c., favours the suppo- 
