The families which, according to natural arrangement, seem to constitute a third division of the great class of birds are principally characterised by the conditions under which they procure their food, viz., by searching for it in situations where it can only be obtained by diligent investigation or laborious exertion. Their diet is usually of a very mixed description, consisting partly of insects and partly of materials derived from the vegetable creation. Many of them were at one time considered to subsist entirely upon the honeyed juices of the fruits and blossoms, among which they spend the greater part of their lives; and, although it is now generally admitted that the insects which abound in the nectared chalices whence they draw their supplies constitute a principal article of their nutriment, they are not the less on that account to be regarded as riflers of the saccharine stores laid up for their use in many a beautiful cup temptingly held forth for their enjoyment. Such are the Honeysuckers and the gorgeously decorated Humming Birds, whose sumptuous garb would seem literally intended to "gild refined gold and paint the lily." A second important group, constituted likewise for the purpose of preying upon insects, has been specially adapted to climb the trunks of trees in search of the innumerable hosts of destroyers that lurk beneath the bark, or in the crevices of wood in progress of decay. These constitute an extensive family, well exemplified by the Woodpeckers; while others, furnished with beaks and feet of very diverse structure, search everywhere for the particular kind of nourishment upon which they are destined to subsist. The name we have selected for this extensive division of the feathered creation was first employed by Reichenbach, although not exactly in the same sense as that in which we are going to apply the term, neither can we hit upon any single character whereby all the species included under this denomination can be easily designated; nevertheless, however they may differ among themselves, there is a certain conformity in their structure, and a general resemblance in their habits, which will probably be appreciated when we have put the reader in possession of the details contained in the following pages. We shall, therefore, at once commence their history, by describing them under the following headings. THE CLIMBERS.