BATRACHIANS. 



(FKOGS AND NEWTS.) 



GENERAL NOTES. 



A TABLE-CASE placed in the passage leading from the Bird- to the 

 Fish-Gallery contains a small series of this class of animals. 

 The softness of their skin prevents their being preserved in a 

 dry condition ; therefore of the thousand species known only 

 a few typical specimens are exhibited. 



Although Batrachia are popularly regarded as Reptiles, they 

 have much in common with Fishes, from which it is by no means 

 easy to separate them. 



They may be defined as cold-blooded * Vertebrata, the majority 

 of which have a pair of lungs which lie below the digestive tract, 

 which for some, or the whole, period of their existence breathe by 

 gills, have three chambers to the heart, and two or no occipital 

 condyles ; their limbs, if present, have not more than five fingers 

 developed, and if, as is rare, they possess dorsal fins, these are 

 merely folds of the integuments without those supporting carti- 

 laginous or bony rays which are found in Fishes. 



The skin is soft, moist, richly provided with blood ; small scales 

 with rounded edges are found only in some of the Limbless 

 forms. 



In the majority of Batrachians the young when it leaves the egg 

 is totally unlike, and afterwards gradually changes into, the form 

 and condition of the perfect animal. This change is called " meta- 

 morphosis." The young or larva is fish-like and breathes by gills, 



* See page 1 with regard to this term. 



