INTRODUCTION. 
Most of the species, if not all, incubate in the holes of trees, laying two eggs at a time, of 
a delicate white. 
The true Toucans, unlike many of the Ara9aris, offer no sexual difference in the colour 
of the plumage ; but the females are rather less than the males in all their proportions. 
The young of both genera assume at a very early age the adult colouring: their large 
bills, however, as might naturally be expected, are not fully developed for a considerable 
period. 
Their flight is straight, and appears not to be effected without considerable exertion; while, 
on the contrary, among the trees, &c., they are as quick and graceful as can well be imagined, 
leaping from branch to branch with the most elegant agility. 
In a state of repose, they turn their heads over their shoulders, the bill being completely 
hidden among the plumage of the upper parts and greater wing-coverts, and the tail raised 
vertically over the back, in which state the bird resembles a ball of feathers. 
The habits of these birds in confinement, as observed on two of the species, have been 
admirably delineated in two papers published a few years since in the “Zoological Journal,” 
by Mr. Broderip and Mr. Vigors. The details given by the latter gentleman are particularly 
valuable: they were derived from the observation of an individual of the Ariel Toucan, kept 
by him for several years, and are almost universally known on account of the numerous reprints 
of them which have been induced by the graceful manner in which they are recorded, no less 
than by the interest of the facts themselves. 
With these few preliminary observations I dismiss the general subject, and proceed to offer 
some remarks on the distribution of the species which have fallen under my notice. 
I. The Toucans are distinguished among the Ramphastidce by the very disproportionate 
size of their bills, and by the comparative shortness and square termination of the tail. The 
general colour of their feathering is black; but the throat and the upper and under tail-coverts 
assume, in all the species yet known, a colouring different from that of the ground. The colour 
of the under tail-coverts appears to be invariably crimson; that of the upper tail-coverts is 
either crimson, white, or yellow, according to the several species. The throat is either white or 
yellow; and is terminated behind by a crimson band, which is in some species very narrow, 
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