56 CROTALUS DURISSUS. 



it appears that its internal structure, in almost all respects, resem- 

 bles the viper. The following is Dr. Shaw's abstract from the 

 account given by Tyson of the more important anatomical pecu- 

 liarities of that reptile. 



"The wind-pipe, as in the viper, as soon as it enters the lungs, 

 consists of semi-annular cartilages, which being joined at both 

 ends to the membrane of the lungs, constitute a free or open 

 channel, thus immediately transmitting the air to the vesicles of 

 these organs which are of very great length, beginning near the 

 throat, and running down three feet in "length. The upper part of 

 them, for the distance of about a foot from their origin, is com- 

 posed of small vesiculse or cells, as in the lungs of the frog ; and 

 which, from the frequent branchings of the blood-vessels, appear 

 of a florid red ; this part tapers proportionally to the body ; the 

 lowest part of it near the heart being moderately blown, is about 

 five inches and a half in circumference; a little lower, for the space 

 of about four inches, the cells gradually disappear, so that they 

 seem at last to form only reticular compages of vavulce cunniventes 

 in the inside of the membrane of the lungs ; the greatest circum- 

 ference here is about six inches; the remaining part of the organ 

 is merely a large bladder, without any cellular subdivisions, and 

 consists of a strong transparent membrane the circumference of 

 which, when inflated, is about eight inches and a half. The lungs 

 in the water-newt, and some other animals, are divided into two 

 large lobes, without cellular subdivisions ; in the frogs, crocodiles, 

 &c. of two lobes with cellular divisions, while in the rattle-snake 

 and viper, both these kinds of structure are comprised, the anterior 

 part of the organ being filled with numerous vesicular subdivisions, 

 while the remaining part is mere lengthened bladder. 



" The oesophagus, or gullet, was two feet three inches in length, 

 and marked by two distinct enlargements of very great size, so as 

 to represent two preparatory stomachs as it were ; nor was the 

 real or proper stomach capable of so much distention as these ; 

 the length of the true stomach or third enlargement, was nearly 

 similar to that of the second enlargement of the oesophagus ; it was 

 much thicker than that part, and resembled in its structure that of 

 the viper. From the pylorus the duct straightened again for about 



