288 



INTEODTJCTION TO ZOOLOGY. 



ments, resembling the scale-like covering of a fish, rather than 

 that of a bird. The poet, in his description of their plumage, 

 has in no way " o'erstepped the modesty of nature : " — 



" In plumage delicate and beautiful, 

 Thick without burthen, close as fishes' scales, 

 Or loose as full-blown poppies to the breeze ; 

 With wings that might have had a soul within them. 

 They bore their ovvners by such sweet enchantment." 



Montgomery's " Pelican Island 



t 



—b 



b'b' 



Fig. 242 Lungs of a Bird.* 



By man, in a rude state of society, feathers were used for 

 trimming his arrows, for decorating his person, and on all 

 occasions of unusual ceremony and state. At present, they 

 are no less valued. Wanting them, the most splendid pageants 

 would lose much of their effect, and " the plumed troop " be 

 shorn of a grace which no other part of its panoply could supply. 

 We must at present consider feathers rather in relation to 

 the birds themselves than to the purposes of use or ornament 

 to which they are applied by man. One obvious advantage 

 to the birds is that of maintaining the warmth of their bodies, 

 or that of their eggs at the time of incubation. All their 



uses, however, we can 



but faintly imagme ; 



we know not in 



• t, trachea ; p, pulmonaiy vessels : o, one of the orifices of the bronchial tubes. 

 The lung v, at the left hand side of the figure, is sliown in its natural state ; that on 

 the otlier side is represented as partly laid open, so as to exhibit the bronchial tubes 

 b b\ by whicli its substance is traversed. 



