530 GENERAL CHARACTERS OP REPTILES. 



certain point, the fabulous Flying Lizards and Serpents of an- 

 tiquity ; but the Dragons of zoologists, instead of being formi- 

 dable animals, like those of poets, are of very small size, and 

 only attack insects. At the epoch in which lived the Icthyosauri 

 and Plesiosauri, of which we have just spoken, there also existed 

 a flying Reptile still more singular than the Dragon. From the 

 structure of its bony framework, we see that, like our Bats, it 

 had the power both of walking on the ground and of flying ; for 

 its posterior feet and all the fingers of its anterior feet, one alone 

 excepted, are formed in the ordinary manner ; but the second 

 finger of the anterior members, is more than twice the length of 

 the trunk, and probably served to sustain a fold of the skin 

 adapted to fulfil the functions of wings. In order to designate 

 this singular conformation, the generic name of Pterodactylus (or 

 finger- winged) has been given to these Saurian fossils. 



469. The movements of Reptiles are generally less lively and 

 prolonged, than those of Mammalia and Birds ; as, indeed, might 

 have been anticipated from the more limited extent of their 

 respiration ; for there always exists, as we have already seen, an 

 intimate relation between the energy of the two functions. Their 

 muscles receive less blood, and present a pale hue. But it is 

 likewise to be remarked, that these organs preserve their irrita- 

 bility for a longer time, after they have been removed from the 

 influence of the nervous system. Among warm-blooded animals, 

 the destruction of the brain and spinal cord, or the section of a 

 nerve, immediately causes a complete paralysis, either general or 

 local ; and in a short time after this has taken place, it becomes 

 impossible to excite muscular contractions, by pricking or other- 

 wise stimulating the affected parts. Among Reptiles, on the 

 contrary, the power of executing movements under the influence 

 of these stimulants, is preserved, in similar circumstances, for a 

 long time ; thus the tail of the Lizard, detached from the body, 

 continues to move for several hours ; and it often happens, that 

 the limbs of a Tortoise which has been dead for several days are 

 seen to move convulsively, when the muscles are stimulated by 

 being pricked. 



470. The brain of Reptiles is very little developed ; the sur- 



