THIRD BRANCH OF ZOOLOGY. 



HERPETOLOGY, (Gr. e^rog, herpetos, a reptile, from ty, 

 herpo, to creep.) 



II. GRAND DIVISION OF THE VERTEBRATES, (Cold-blooded Animals,) 



SECTION I. 



THE second grand division of the Vertebrates, or Cold-blooded 

 Animals, includes REPTILES and FISHES. 



REPTILIA, (Lat. reptilis, a reptile, from repo, to creep.) REP- 

 TILES. The science which treats of Reptiles is called Herpe- 

 tology, (or Erpetology.) They form one of the most remarkable 

 of the vertebrate classes of the Animal Kingdom. They are 

 highly characterised by the vertebral column, the articulations 

 of which, in most recent adult forms, are spherically convex at 

 one extremity and spherically concave at the other. The num- 

 ber of vertebrae varies exceedingly. As, for example, in the 

 Surinam toad, (Pipa,) there are seven, and in the Python upwards 

 of four hundred. The ribs also occur in various stages of de- 

 velopment. A general survey of these creatures brings to view 

 wonderful varieties of form and structure by which they are 

 adapted to different localities. Some dwell on the land ; others 

 in the ocean. Many of them are found in rivers and morasses, 

 and some are even arboreal in their habits, living amidst the foli- 

 age of the trees,/ intertwined with the branches, or flitting, with 

 bird-like swiftness, from leaf to leaf or from branch to branch, 

 in pursuit of their insect food. Though found in different lati- 

 tudes, the hotter regions of the globe are the great nursery of the 

 Reptiles ; in tropical countries, they actually teem, swarming in 

 sandy deserts, among dense and tangled brushwood, in humid 



