PASSERES. 



I. Historical Eemarks on the Distinction between Singing Birds 



AND OTHER PASSERINES, FOUNDED ON THEIR VoCAL MuSCLES. 



CuvierI was the first to give a description of the organ of voice, or lower larynx 

 of Singing Birds, and to his work every one has since had recourse. According to him, 

 Singing Birds possess a muscular organ of voice made up of five muscles on each side of 

 the lower larynx, which arise from it and from the trachea, and pass obliquely downwards, 

 partly to the anterior, and partly to the posterior ends of the highly moveable half-rings 

 of the bronchi, raising the second and third half-rings by their anterior and posterior 

 extremeties, and altering their position, as well as that of the vocal cords, with respect 

 to the stream of air. 



These muscles are the long anterior and posterior elevators of the third half-ring ; the 

 small constrictor longitwdinalis, which is attached to the posterior elevator, and to the second 

 half-ring; the constrictor obliqmcs, which also moves the hinder extremity of the second 

 half-ring, and the constrictor transversalis, which goes to the anterior end of the same 

 half-ring. 



This group of muscles is characterised by the fact, that they work not on the 

 middle convex portion of the half-rings, but on their ends, to which they diverge forwards 

 and backwards after leaving the sides of the trachea. The consequence of this division 

 of the moving force is a complete change of position, and a rotation of the half-rings, as 

 described by Savart, which is consequent on the raising of their ends. It is not my aim 

 to describe the mechanism of this larynx or of its cords, memhrana tympamformis and car- 

 tilcKjo arytaenoidea, which latter is so often present in this region, nor the other parts 

 which may be observed here, since they may be supposed to be known from the descrip- 

 tions of Cuvier and Savart. Cuvier found this complex muscular organ of voice in 

 Sparrows, Titmice, Blackbirds, Thrushes, Buntings, Larks, Ravens, Rooks, Nuthatches, 



• Magasin encyclopaedique ou journal des sciences, des lettres et des arts, redige par Noel et Warens, 

 T. II. N. VII. p. 330 ; Reil's Archiv f. Phys. V. p. 67. 



