3o6 GENERAL ORNITHOLOGY part ii 



muscles (anterior external, anterior internal, intermediate, and 

 posterior, besides the extrinsic sternotracheales), as figured in ^^, a, 

 h, c, d, and e, Macgillivray is said to have understated the full oscine 

 number, which is five or six. In the raven, Owen describes five, 

 without counting the sternotrachealis : hrmichotrachealis anticus, 

 anterior external ; bronchotrachealis posticus, posterior external ; 

 bronchotracJiealis brevis, posterior internal ; bronchialis anticus, anterior 

 internal; and bronchialis posticus. The general arrangement, how- 

 ever, is fairly indicated by Macgillivray in ^^, where on the side of 

 the syrinx, the muscles are seen to diverge from the tracheal lateral 

 line to go to ends of the bronchial semi-rings. 



The student will understand that my description is particular 

 only as regards the oscine syrinx; that in birds at large every 

 possible modification, almost, of lower tracheal and upper bronchial 

 rings occurs, and with various musculation, or with none. The 

 non-oscine rule for the muscles is, one on each side, if any ; and 

 insertion into mid-parts, not ends, of the bronchial half-rings. The 

 latter character chiefly distinguishes the non-oscine syrinx when it 

 has several muscles. As to situations of the syrinx, three have 

 been recognised : the ordinary bwndiotracheal, in formation of which 

 both bronchi and trachea take part ; the tracheal, only known to 

 occur in some American Passeres, as in Thamnophilus and 

 Opetiorhynchiis, situated wholly in the trachea, the lower part of 

 which is extensively membranous ; and the bronchial, wholly in the 

 bronchi, as in Crotophaga and Steatm'nis. 



The Song of Birds unlocks the great secret of Genesis to those 

 who can hear the keynote. It is the closest approach in animate 

 nature to the ringing of the hydrogen bells in the physics of light. 

 The musical instrument figured (101, i'^) is the identical pipe the 

 " great god Pan " first fashioned for a legacy to all time, as so 

 sweetly said by Mrs. Browning : — 



" He tore out a reed, the great god Pan, 



From the deep cool bed of the river. 



The limpid water turbidly ran. 



And the broken lilies a-dying lay. 



And the dragon-fly had fled away, 



Ere he brought it out of the river. 



" ' This is the way,' laughed the great god Pan, 

 (Laughed while he sate by the river !) 

 The only way since gods began 

 To make sweet music, they could succeed.' 

 Then dropping his mouth to a hole in the reed, 

 He blew in power by the river. 



