52 ORGANS OF BREATHING. 



have been known to remain a surprising length of time in a 

 fasting state. A favourite hen, which had been missed for 

 upwards of four weeks, was fortunately found at the bottom 

 of a deep well by a person who went down to repair it ; the 

 poor bird when discovered was perched on a small piece of 

 timber floating on the water, and when taken up was in a 

 very exhausted state, but soon recovered. 



A Goose was accidentally shut up in a shed, and supposed 

 to have been carried away by a fox, when, at the expiration 

 of three weeks, it was discovered alive ; for a few days it 

 continued in a weak state, but gradually resumed its strength. 



Having taken a short view of the framework and internal 

 construction of a bird, with reference to the disposal of its 

 food, we shall next consider some other of the vital functions, 

 commencing with those of breathing and voice. The lungs of 

 men and animals occupy, as is well known, a large portion of 

 the chest, whereas, in birds, the space occupied is not only 

 much smaller, but the lungs themselves are of a more firm and 

 compact texture. At the same time they are most plentifully 

 supplied with air-cells, communicating with other cells, pro- 

 fusely distributed over every part of the system, by which 

 their bodies are in a manner blown up and rendered buoyant : 

 a considerable portion of the skeleton, moreover, as we have 

 shown, being formed into receptacles for this light and elastic 

 fluid, of which birds partake in so much greater a degree than 

 most other portions of the creation. In fact, a bird, destined 

 as it is to live in air, may be almost called an absolute air- 

 vessel, so completely does air fill up and circulate through' 'it 

 its whole frame. While men and other land animals breath 

 in air through the nostrils alone, a bird respires through a 

 variety of other channels. A wounded Heron was observed 

 to live a whole day, breathing solely through a broken portion 

 of the wing-bone.* Other experiments have confirmed the 

 fact ; the fractured portion of a bone that had been separated, 

 when immersed in soap-and- water, was observed to emit bubbles 



* See Linncean Transactions, vol. xi. p. II. 



