OF NORTH AMERICA. 333 



ceive an equal propoitioii of the fluid ; the risiht aorta rc- 

 cei\es a fi;ieater quantity, and the left aorta must cease to he 

 distended with a surplus othlood. whilst tiiat part of it eoiitiiin- 

 e<l in the left ventricle must act u|)on the valve placed bel'ore 

 the orilice leading to this same left aorta, and thus prevent 

 the flowing of the blood fiom that artery. In this state, the 

 other arteries are supplied wiili nearly pure blood. Sucli is 

 the result of my observations. It appears that M. Cuvier, 

 whose anatomical knowledge is well known, has dissected 

 only a small alligator whicii was sent alive from the West 

 Indies, which, tliough it died on the passage, arrived in time 

 to be examined. Youth, disease, and several other causes, 

 may have rendered this body an unfit sul)ject to examine 

 with certainty those organs ; which I have dissected several 

 times in laige animals, soon after their being deprived oi 

 life. 



In the alligator, the muscles are not very numerous, but 

 extremely large in general, and strong; tliosc of an animal 

 killed as it has just left its winter retreat, are white and flac- 

 cid ; they stand several days in the open air without any al- 

 teration, whilst tlie muscles of one killed in the summer are 

 red, more firm, and rcseml)le those of any animal with dou- 

 ble circulation, except in their great contractile power after 

 apparent death. I shall enumerate those muscles which are 

 most conspicuous. On the thorax, there is an extensive pec- 

 toral nmscle, covering nearly all 'he ribs, and inserted on 

 the humerus; there is al)0ve, a flat and long muscle extend- 

 ing from the sternum to the lower jaw by one fasciculus, 

 and to the larynx by another ; one extending from the 

 clavicle to the larynx ; anotlier arisirig from the os hifoidcs^ 

 covering!; the larynx, and ending at the point of the tongue; 

 and a last smaller nmscle, arising frou) the os hj/oides, and at- 

 tached to t!ie lower jaw. Thesr muscles having cotmections 

 with the throat, brim; down tlie larynx and the tongue, and 

 probably assist deglutition. The most important muscle of 

 the abdomen is one that arises from the os pubis; it passes 

 under the abdominal ribs which have been described by M, 



