218 ON THE ALLIGATOR 



this opinion, l)ut gives no particular description : in his Com- 

 parative Anatomy, liowever, he describes the structure of the 

 heart in the crocodile. 1 shall here sul)join a literal transla- 

 tion of this passage, which must be compared with my ob- 

 servations: — 



" Heart of Reptiles. 



" We shall first describe the heart of crocodiles, because 

 it furnishes us with an example of the most complicated 

 structure that we have observed in animals of this order, or 

 indeed in the whole class of reptiles. 



" The pericardium adheres, as in the chelome?is, to the pe- 

 ritonjeum, which covers the convex surface of the liver, and 

 its point is retained by a very strong tendinous chord to the 

 free portion of the sack, which is extremely thick, and ex- 

 teriorly of a fibrous structure. It is fixed on one direction 

 between the two lobes of this viscus ; on the other, between 

 the two lungs. The auricles, a little smaller than those of 

 the cheloniens, have however the same relations, thick pa- 

 rietes, closed by strong fleshy columns, crossing in different 

 directions. The ventricle, properly so called, presents an 

 oval form, and very thick parietes ; its cavity is divided into 

 three cells, cummunicating with each other by many orifices, but 

 giving, nevertheless, to the blood which they receive a suffi- 

 ciently determinate course. One of these cells is inferior, and 

 on the right : the auricle of the same side pours out the blood 

 which it receives from the veins of the body by a large open- 

 ing, bordered witli two valves and placed at the most ad- 

 vanced part of this cell : upon the left side of tliis same cell, 

 but still before, we find the opening of the left descending 

 aorta ; and behind this opening, an orifice which leads to the 

 smallest of the tliree cells, placed at the middle part of the 

 base of the heart, and into which opens tlie common trunk of 

 the pulmonary artery. 



"Consequently, the blood which arrives from the right 



