332 PHILOSOPHICAL TRANSACTIONS. £aNNO 1766- 



heard either wild or river swans sing: and therefore he doubts it much. But if 

 they do sing, the length of the pipe contributes nothing towards it; it is the 

 glottis, which forms the voice, and modulates it, whether the pipe be long or 

 short: besides, none of the song, or speaking-birds, have any flection in their 

 pipes, that we are acquainted with. 



The crane is the next that Dr. P. mentions, which has such a turning of the 

 asperia arteria in the keel of the sternum ; but the volution of this bird is round 

 within the bone, and may be compared to that of a French-horn ; whereas that 

 of the wild swan is straight within the bone, and may be compared to a trumpet ; 

 yet the entrance of this into the sternum, and its exit, and its passage into the 

 cavity of the thorax, are similar to those of the swan. This is a bird which 

 cannot go upon the water, being no more capable of swimming than a common 

 cock or hen. His feathers will not admit of it; and, having no webs to his 

 toes, he is unable to swim. It is somewhat surprising that not one of the tribes 

 which are similar to the crane, such as the herons, storks, bitterns, &c. has any 

 such structure of the asperia arteria ; and yet they all feed upon fish or water 

 insects. We are however, to consider that the heron chiefly haunts brooks, 

 springs, and the narrow heads of rivers, where he seeks his food, and finds it 

 with ease: but the crane is under a necessity of immersing its head, and remains 

 a considerable time in that situation upon strands and marshes: it is also a bird 

 of congress; for at certain seasons, a multitude of cranes flock together, and 

 rise upon the wing to a great height in the air, being birds of passage, and 

 they are by many authors said to travel from most parts of Scythia to Egypt, 

 where, for a certain season, they remain about the Nile, and the great lakes of 

 that country. Perhaps this elongation of the windpipe in them may be also of 

 use, in their great flight through various degrees of rarefied or condensed air, in 

 the variety of climates through which they pass. 



The Indian cock, Gallus Indicus of Aldrovand and Longalius, and Gallus 

 Persicus of Johnston, the Mutu Poranga of Margrave, is not the Coq d'Inde, 

 or Turkey cock, but by the last author ranged among the pheasant tribe; this 

 bird has a plication of the aspera arteria, but not so considerable as either of the 

 forementioned swan, or crane: for it descends in a straight line, along with the 

 oesophagus, to the middle of the jugal bone, without and above the thorax, 

 where it is spread and fastened on each side. Then, turning backwards, being 

 somewhat flat, it makes a fold upward to about an inch and half high, and there 

 being made fast again, by a strong membrane, it doubles down and passes into 

 the thorax, terminating by two bronchia in the lungs: and where it is fastened 

 and folded, that is, in the flat parts, it is triple the circumference of any other 

 part of the pipe. This bird, and another of the same species, were dissected by 

 the Royal Academy of Sciences, and this structure of the pipe appeared in both ; 



