CHAPTER XIX 



THE AMPHIBIA (FROGS, TOADS, NEWTS AND 

 SALAMANDERS) 



The Amphibians or Batrachians, as a class, show a cer- 

 tain proclivity for living in or near the water, and in almost 

 all cases where species, as in frogs and toads, have taken 

 to living on land they return to their ancient aquatic 

 habitat to breed. In general the amphibians have a 

 smooth skin devoid of scales or armor, and furnished with 

 numerous mucous or slime glands which, in terrestrial 

 species, serve to keep the skin constantly moist. The 

 limbs in the amphibia are very different from those 

 of fishes in that they are typically of the five-toed type 

 and fitted for walking or leaping, like those of higher 

 vertebrates. 



The amphibians at present existing on the earth may be 

 divided into three groups, the Urodeles or tailed am- 

 phibians (newts, salamanders, etc.), the Anura, or tailless 

 forms (frogs, toads), and the Ccecilians which comprise a 

 few legless worm-like species living in warm climates. 

 In some of the lowest of the tailed amphibians we meet 

 with many interesting fish-like characters such as the 

 possession throughout life of external gills. These forms 

 naturally live permanently in the water, although they are 

 generally furnished also with lungs for breathing air. 

 The mud-puppy, Necturus, is one of these primitive forms 

 which is not uncommon in lakes and streams of the north- 

 eastern United States. Another is the peculiar Proteus 



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