256 STUDY OF NATURAL HISTORY. 
different in different individuals. Thus, in the horse, 
where the tail is more developed than in any other 
quadruped, it may be looked on as more ornamental 
than essential: at least, we know it is not con- 
nected so intimately with the habits of the animal, 
that its loss leads to the impossibility of supporting 
life. But among the long-tailed monkeys of 
America, this result would inevitably follow; their 
tail is prehensile, and, by being employed as a fifth 
hand, in climbing trees, is absolutely essential to 
them in procuring the fruits upon which they live. 
We have examples precisely analogous to these, in 
the class of birds. The glory of the peacock is its 
tail; it is, indeed, a splendid ornament, but it is 
an ornament alone. And we know, from the habits 
of these birds, not only in a state of captivity, but 
in their native regions, that they can search upon 
the ground for their usual food just as well without 
their tail as with it: but with the parrots, and more 
especially the woodpeckers, the case is different ; 
here, also, the tail is highly developed, but in a very 
different way. In the parrots, it performs the double 
office of aiding flight, and the power of climbing. 
Those who have witnessed the lofty and arrowy 
course of the splendid mackaws of the New World, 
know that this celerity of motion would be utterly 
lost if the tail were of any other structure ; while 
every one who has watched a parakeet, even in the 
confinement of a cage, may have remarked how 
much this member contributes to facilitate the habit 
of climbing possessed by these elegant creatures. 
Still, however, the utility is only seen at its maximum 
in the most typical climbers, or the family of wood- 
