STERNA OF THE COI.UMBAD^. 361 



whole, our admiration changes to the most complete 

 astonishment, because the utmost effort of our powers 

 can no more fathom the depth of design, which is 

 apparent in w^hatsoever portion of nature we study, 

 than the span of our fingers can measure the exten- 

 sion of the universe. 



STERNA OF THE COLUMBAD^. 



Though the birds belonging to this group are not 

 climbers, and the greater number of them seek their 

 food upon the ground, chiefly vegetable, though some 

 of them also eat insects, yet they retain in the sternal 

 apparatus some of the characters of the climbing 

 birds : and there are, among the species found in 

 warm countries, some which have the colours of the 

 plumage as brilliant as any of the climbing or zygo- 

 dactylic birds. They in general perch in trees, or in 

 the holes and on the ledges of rocks ; but there are 

 some species which reside chiefly on the ground. 

 There are also some which, in their general appear- 

 ance, and partially also in the form of the sternum 

 and its apparatus, have some resemblance to the gal- 

 linaceous or poultry birds ; and of these, as is the 

 case in that order, there are some which nestle in 

 trees and some on the ground. The race are indeed 

 considerably diversified ; but still the more typical 

 ones, in many particulars of their sterna, preserve a 

 resemblance to the climbing birds. The sternum of 

 the rock-dove, which is usually considered as the 

 parent stock out of which the numerous varieties of 

 domestic pigeons have been bred, may be selected as 

 about the average. 



In the development of its keel, this sternum bears 

 some resemblance to that of the parrot; but it is 

 better formed for flight, as the keel is more advanced 



