ORDER OPHIDIA, 303 



The mesentery forms a very narrow fold, which does not 

 proceed immediately from the vertebral column, and between 

 the laminse of which the blood-vessels creep without being 

 divided. 



There are no epiploa, properly speaking, in the ophidians. 

 Many of them, however, have appendages under the intesti- 

 nal canal loaded with fat. 



Lymphatic vessels have also been recognized in these ani- 

 mals : but the ganglia which appertain to the system of these 

 vessels have not been yet discovered. 



The kidneys are extremely elongated, and formed of a great 

 number of lobes, separated, and as it were enchained, one be- 

 fore the other. From each of these lobes comes the urine, 

 by a particular branch, into a common conduit, which follows 

 the internal edge of the organ, and constitutes the ureter, 

 which, when arrived above the cloaca, dilates into a small 

 oval vesicule, before it is terminated by a separate orifice. 

 In consequence of this last disposition, the urinary bladder 

 is wanting. 



The growth of the ophidians is rather slow. They 

 live a long time, and the lethargy to which they are sub- 

 ject in the winter season, appears to suspend their exist- 

 ence. There are some species which, in the course of time, 

 attain to the prodigious length of thirty or forty feet. The 

 giant-serpent observed by Adanson, in Senegal, must have 

 been one of this kind ; as also that against which Regulus was 

 forced to bring his machines of war to bear, if indeed it be 

 possible to credit the report of Valerius Maximus, that it 

 was one hundred and twenty feet in length. 



Circulation, which always goes on slowly in these reptiles, 

 is yet subordinate to the act of respiration, to the temperature 

 of the atmosphere, and to the development of the passions. 

 The heart has but one ventricle and two auricles, of which 

 the right, which receives the blood of the body, is the 



