SONG OF BIRDS. 



179 



The vocal apparatus in Birds, represented in Fig. 69, is 

 very complicated, and differs from the human larynx and trachea. 

 It consists of a kind of osseous chamber ; which, however, is only 

 a swelling in the arterial trachea at the point where it bifurcates 

 and enters the breast to form the bronchial tube. It is this 

 formation, called the lower larynx, which constitutes the organ of 

 song. Five pairs of muscles, attached to the walls of this chamber, 

 stretch or relax the vocal chord, by which means they enlarge 

 or diminish the cavity of the larynx. Whoever has watched a bird 

 singing must have noted the swelling and contracting of its throat 



Fig. 69. Vocal Apparatus contracted and distended. 



as it poured out its melody, modifying in a thousand ways the 

 tension of the vocal chords, and producing those marvellous modu- 

 lations the perfection of which must always be a subject of astonish- 

 ment and admiration. 



The song of Birds must be the expression of some sentiment; 

 for they sing as much for their own pleasure as to charm those who 

 listen to them. While filling the woods with their melodious accents 

 they direct their gaze on all sides, as if proud of their talents, and 

 desirous of gathering the tribute of admiration to which they feel 

 themselves entitled. Their song varies with the season, but it is in 

 the early spring their efforts are most admired for their beauty of 

 harmony. Can anything be more fascinating than the warbling of the 

 linnet, the piping of the goldfinch, or the melodious cadence of the 

 nightingale, as it breaks the silence of the woodland during the 

 serene nights of leafy June ? 



Our landscapes would be sad and mute indeed without these 



