OF NORTH AMERICA. 225 



torn of this bag there is a white glanihilar substance, which, 

 when opened, presents no cavity discernible by the naked 

 eye. and is destitute of smell; the fore extremity of this is 

 terminated l)y a similar sul)stance, in the form of a cord, 

 which is attached to the extremity of the cornu of the os 

 hijoides. Several gentlemen informed me that when the 

 animal is wounded or angry, he contracts the lower mus- 

 cles of his neck, and the two bags protrude. I liave not been 

 able to discover the use of these organs. It has been said, 

 that in the alligators and turtles, the heart beats for a long 

 period after being extracted from the body ; for my |)art, al- 

 though I dissected the animals immediately after they were 

 killed, nay whilst their limbs still preserved a sort of invo- 

 luntary motion. I always found that the heart had entirely 

 ceased to contract. 



I cannot close my remarks without mentioning a circum- 

 stance which I am unable to explain : Whilst dissecting these 

 animals. I often found small hags, apparently formed by the 

 cellular substance ; they contained a black residiunn. and 

 some fine gravel: in one of them I discovered the elytrum 

 of an insect of the genus Dijtiscus, well preserved. There 

 %vas no connection with the suriounding parts, and no cica- 

 trix could be perceived in the skin near them, 1 even found 

 one of these bags under the sternum. I leave it to future 

 observation to explain liow they are formed. 



This is the amount of my observations on this singular ani- 

 mal during my residence in South Carolina. I regret that 

 it is not more complete. I have endeavoured however to 

 make known such facts only as appeared to me to be new, 

 omitting those which are already known. 



Since writing the above, I have had an op|)ortunity, in 

 conjunction with Dr. Harlan, of minutely dissecting a young 

 alligator. The animal l)eing injecli'd, furnished clearer de- 

 monstrations of the correctness of mv lemaiks. 



