Account of Observed Forms of Larynx. 2)7 



The union of Cinchis with the South American birds by Swainson and Gray is 



wrong. Cinchis has a complex muscular organ of voice, which I also found in the genus 

 Timalia Horsf. among the before-mentioned genera. 



(vii.) Organ of Voice of Trochilus. 



The larynx, lying in the neck of the Humming Bird, which does not possess musculi 

 sternotracheales, has been already examined by Meckel, Audubon, and others, but its structure 

 has not been correctly recognised by any of these observers. The organ is thus arranged in 

 the various subgenera of Trochilus, viz. Campylopterus, Phaiitornis, Lampornis, OrfhorIii/nc7ius, 

 and Ornismyia : — it possesses two muscles very peculiarly broken up; the first half-ring of the 

 bronchus is excessively small, and inserted between the ends of the second large half-ring 

 and the lower larynx ; the ends of the second half-ring are fastened to the larynx itself, 

 their posterior extremities are very large, and triangular ; two sides of the triangle receive 

 the muscle which, arising from the larynx anteriorly, below the middle line, passes obliquely 

 outwards, and then bends backwards and downwards ; from this end of the second half-ring 

 arises a second muscle, which has hitherto escaped notice ; this goes in an opposite direction 

 forwards and downwards, and is inserted in the two following rings and the third, which, 

 as all that follow it, is a perfect ring. The small memhrana lynipauiformls possesses a 

 rounded cartilage. 



(viii.) Oi'gan of Voice of Colius. 



Among the Passerines of the Old World, which do not possess the complex muscular 

 organ of voice, this genus is, as far as is yet known, the only one whose larynx is peculiar. 

 It possesses a thick vocal muscle, and is peculiar from the fact that the first bronchial 

 ring forms an osseous triangular shield over the second and third. Into this shield is in- 

 serted the muscle, which, however, also gives off smaller branches to the anterior part of the 

 second and third half- rings. The vocal band lies on the upper edge of the first half- ring, 

 which is completely osseous. I have examined C. capensis and C. qniriwa Less. 



It has often been lamented that the anatomy of birds is so uniform, that the labours of 

 Zoologists receive but little assistance from their anatomy. This remark is very true ; 

 but it must be borne in mind that it is not true for all parts. The organ of voice is 

 an exception ; there are in it important characters, distinguishing genera and fiimilies, 

 which seem, in every external character, to pass into one another. And if nature shows 



