Account of Observed Forms of Larynx. 21 



IV. Account of Observed Forms of Larynx. 



(i.) Organ of Voice of Chasmarhynchus. 



That the lower larynx of Chasmarliynclivs is very muscular has been long known 

 from a remark of Prince Max von Wied ^ and from the figure which he gave of the larynx 

 of Chasmarhynchus nudicoUis Spix. At first one only recognises from the figure that 

 the lower larynx has a very highly muscular covering, but it is uncertain whether the 

 organ is formed on the type of the so-called muscular organ of voice or not. These 

 birds are remarkable for their harmonious voice, which Prince Max compares to the 

 tone of a clear-sounding bell ; it is uttered once, lasts a long time, and is generally 

 repeated again soon, just as if a smith repeatedly struck his anvil. Marcgrav made 

 a very similar comparison as to the voice of the Guirapunga, C. vanegatus: Duplieem 

 autem sonum edit promiscue, una vice quasi quis seeuri percuteret cuneum ferreum in silva 

 (cod, cick), altera autem quasi quis campauam fissam tangeret kur, kur, kur, cet^. According 

 to Rich. Schomburgk, whose observations were made on C. carimculatus, the tones are 

 modulated also; consequently the mechanism must be carefully studied. I examined 

 two of the examples sent home by Schomburgk in spirit of C. caruncwlatus, and two 

 larynges sent by Sello, with the trachea and tongue of another species, probably 

 C. nudicoUis, as the form of the organ quite agrees with the figure of the same given 

 hj Prince Max. These two larynges I found, with other unnamed material sent by 

 Sello, in the stores of the Anatomical Museum, and they struck me at once by their 

 extraordinary covering of muscle, which holds the same relation to the larynx of the 

 Sino-ino- Birds, as the muscular stomach of a Fowl to that of the Singing Birds. I 

 was long unable to make out from what bird this marvellous larynx came, but when 

 I examined the Chasmarhynchus sent home by Schomburgk, the matter was at once 

 clear. These larynges of Sello agree in all essential points, exactly, with the larynx 

 of C. carimculatus, and with no other bird ; they are only .more muscular, and conse- 

 quently diff'er in the arrangement of the vocal bands. The examination also of the 

 trachea, tongue, and mucous membrane of the mouth, rendered the agreement more 

 remarkable, namely, in the exactly similar tongue, in the trachea which anteriorly is 

 wide, and gradually narrows, and in the blackish colour of the mucous membrane of the 

 mouth. By the assistance of the figure of Prince Max the larynges of Sello can be 



1 Beitr'age zur Naturgeschichte von Brasilien. B. III. 



2 Hist. nat. Brasiliae, Lugd. B. 1648, p. 202. 



