BILLS OF THE TOUCANS. 207 



copses and open forests rather than those which are 

 deep and tangled. 



Between the cuckoos and the toucans there occur 

 several genera with bills very much diversified in 

 shape, and with the owners of course as miscellaneous 

 in their feeding. In general, however, they are insec- 

 tivorous, but they also eat small earth animals, and 

 sometimes the more succulent vegetable substances. 

 The keel-bill is named from the strong projecting 

 ridge or keel on the culmen of the upper mandible, is 

 one of the best known and most remarkable of these, 

 remarkable alike for the universality of its agreement 

 with its own species, and with all other creatures,except- 

 ing those that serve it for food, and for the miscella- 

 neous nature of its feeding. It alights on the backs 

 of domestic animals, and clears their coats of insects. 



Of all this order, however, and indeed of all birds, 

 with the exception perhaps of the hornbills, this in- 

 strument is most singularly formed in the toucans. 

 There are two genera ; toucans proper (Rhamphastos}, 

 and aracari (Pteroglossus], of which the systematic 

 names are not very descriptive, as each has the cha- 

 racter expressed by both. Each is rhamphastos, 

 large bill, or, colloquially, " beaky ;" and each is 

 pteroglossus, winged-tongue, or feather-tongue ; but 

 the toucans have the bill largest, always exceeding 

 the section of the head, and sometimes as large as the 

 whole body, while the bill of the aracari is not thicker 

 than the head. The following sketch will show the 

 general form of the bill of the toucan. 



The general substance of this vast bill is cellular, 

 with the partitions of the cells so very thin that, 

 large as it is, it is very light. In the living state the 

 covering membrane is very finely coloured with 

 prismatic reflections, but these soon fade after death. 



