FROGS. iy 



Serpents are eaten. But viper-broth, which was known to Hippo- 

 crates, we believe, is not to be found now as an article of food. 



As we have already remarked, the peculiar nature of their 

 organisation leads Reptiles and Batrachians to seek the warmer 

 regions of the earth. It is in those regions that they attain the 

 enormous dimensions which distinguish certain Serpents ; there, too, 

 they secrete their most subtle poisons and display the most lively 

 colours, which, if less rich than those of Birds and . Fishes, are not 

 less startling in effect. Many Serpents and Lizards glitter with 

 radiant metallic reflections ; and some of them present extremely 

 varied combinations of colour. Chameleons are found in the same 

 localities, but in the Old World only ; these and some other Lizards 

 are remarkable for changing their colour, a phenomenon which is 

 also seen among the Frogs, but in a smaller degree. 



Reptiles and Batrachians were numerous in the early ages of our 

 globe. It was then that those monstrous Saurians lived, whose 

 dimensions even are startling to our imagination. The forms of the 

 Reptiles and Batrachians of the early ages of the earth were much 

 more numerous, their dimensions much greater, and their means of 

 existence more varied than those of the present time. Our existent 

 Reptiles are very degenerate descendants of those of the great 

 geological periods, unless we except the Crocodiles and the gigantic 

 Boas and Pythons. Whilst the Reptiles of former ages disported 

 their gigantic masses, and spread terror amongst other living 

 creatures, alike by their formidable armature and their prodigious 

 numbers, we are happy to say that now they are reduced to fewer 

 varieties. There are now but little more than 1,500 species of 

 Reptiles and Batrachians described, and only 100 of these belong to 

 Europe.* 



Batrachia. 



Animals which compose this class have long been confounded 

 with Reptiles, from which they differ in one fundamental peculiarity 

 in their organisation. At their birth they respire by means of gills, 

 and consequently resemble Fishes. In a physiological point of view, 

 at a certain time in their lives these animals are Fishes in form, 

 habits, and organisation. As they progress in age they undergo 

 permanent metamorphosis — they acquire lungs, and thenceforth an 

 aerial respiration. It is, then, easy to understand that these animals 

 hold a doubtful rank among Reptiles, which are animals with an 



* Vide subsequent notes on this subject, in p. 28, &c. 



