83* FHILOSOPHICAL TRANSACTIONS. [aNNO I766. 



making so great a noise, that they are heard a great while before they are seen. 

 Again, by his short account we may easily learn, that they are not the crane that 

 is described in this paper, because the colum has a volution of the wind-pipe on 

 both sides of the keel of the sternum, the crane but one; and it seems, from the 

 likeness of the serass to the colum, he says, that the former is a species of the 

 latter: nor can we have room to suggest that these birds are of the wild goose 

 kind; because he mentions the brand geese first, without taking the least notice 

 of their asperaarteria; and confines the rest of the paragraph to the other two, 

 calling the one a species of the other. 



These are all the birds that have hitherto come to notice, having this remark- 

 able flection in the aspera arteria; it now only remains to mention further that of 

 the land tortoise, which Dr. P. brings in here on account of a similar formation 

 of that organ in him. Having never dissected a land tortoise himself, he has 

 recourse to those that have; and accordingly he finds its parts examined by a 

 celebrated physician of his time, Velchsius, from whom Blasius has taken it, and 

 by the Academy of Sciences. Blasius has however made the anatomical distribu- 

 tion of its parts and their explanation: from whom Dr. P. takes the figure; and 

 though this last author quotes Severinus and Coiterus as dissectors of the 

 tortoise, as well as Velchsius, yet this latter only mentions the windpipe. In 

 Blasius's figure, this pipe, for a few inches from the epiglottis, is single, but soon 

 divides into two; and as it descends in company with the oesophagus, it forms a 

 folded ring outwards on each side, and turns down again to enter the lungs: so 

 that the animal has the advantage of a double aspera arteria, with a volution in 

 each: which shows that this provision is intended to contain a greater portion of 

 air thaJi ordinary while he is under ground in winter. 



The tortoise dissected by the Academy of Sciences, was a large land tortoise 

 from the coast of Coromandel; in which was found a bifid windpipe; each 

 branch is said to be 6 inches long, but no mention is made of the volutions in 

 this land tortoise; which, one would think, being so remarkable a variety from 

 the common standard, ought not to escape the notice of such able anatomists. 

 Yet it was found, by several experiments, that respiration was very slow and 

 unequal in this animal, as well as in the camelion ; the Academicians observed 

 several tortoises for a long time together, and have taken notice that they 

 sometimes cast forth a cold breath through the nostrils, but that is by long 

 intervals and without order; and that the camelion is sometimes half a day 

 without one's being able to discern in him any motion for the respiration. From 

 this it is easily seen, that they can retain inspired air a long time : and the Aca- 

 demicians therefore think, that the principal use of the lungs in tortoises, is to 

 render themselves specifically lighter or heavier in the water, by their inflation 

 and compression at will, as fishes do by their swimming bladders ; indeed such a 



