CHAPTER XVI 



THE STUDY OF AMPHIBIANS 



THE amphibians of to-day such as frogs and toads, newts and 

 salamanders are the descendants of those vertebrates that long 

 ages ago made the transition from aquatic to terrestrial life. 

 Amphibians were the first animals to have fingers and toes, and 

 the first vertebrates to have vocal cords. Some other acquisitions, 

 such as lungs and a three-chambered heart, which are hinted at 

 in the double-breathing mud-fishes or Dipnoi, are securely estab- 

 lished in Amphibians. 



FIG. 35. Spotted or fire salamander Salamandra maculosa a common 

 amphibian on the continent, but not found in the British Isles. The ground 

 colour is black with large irregular yellow patches. It is an interesting 

 animal for a vivarium, and usually thrives if provided with a moist and cool 

 retreat. It may be fed on earthworms, grubs, slugs, and woodlice. Like the 

 toad and many other amphibians it secretes a poisonous juice from its 

 numerous skin-glands. It may be described as viviparous, for the egg- 

 membrane bursts before or just after birth, liberating larvae about an inch 

 long, which are able to eat from the first. 



There is almost always a metamorphosis in the life-history, 

 and the larvae bear gills. These may be retained throughout life, 

 but they disappear in the great majority, the breathing being 

 effected by lungs and also through the skin. A hibernating 



