AMPHIBIA. 327 



The front limbs are formed later as buds in the branchial 

 cavities. The next stage of the tadpole is just like a tailed 

 amphibian : the tadpole tail still exists with the four limbs, as 

 we see in the newt (7). During this metamorphosis more and 

 more of the blood-supply is passed to the pulmonary sacs as the 

 larva develops, and when the adult stage is reached, and the 

 creature becomes purely aijrial and terrestrial, all sign of the 

 branchial circulation has become obliterated by a gradual process 

 of elimination. The tail eventually disappears (8, 9). 



The adult Anoura are all fond of damp situations. Their 

 skin is moist. The adults always feed upon insects, slugs, 

 ■worms, &c. Anoura or Tailless Amphibia have a soft skin, 

 with rarely any trace of exoskeleton. The two chief groups 

 are the Bufonidce or Toads and the Ranidce or Frogs. The 

 Toads have no teeth in their jaws, and always a tongue. 

 The hind-limbs are not so very abnormally developed, the toes 

 being only imperfectly webbed; the toes of the forefeet are 

 always free, and the skin is rough and granulated. The two 

 English species are the Common Toad {Bufo vulgaris) and the 

 Natterjack (B. calamita). The latter, which is a large toad, is 

 somewhat rare. Bufo vulgaris is a most beneiicial animal : 

 when kept in greenhouses it does an enormous amount of good, 

 clearing off slugs, snails, and other vermin of a night. 



The Toad catches its prey only when it is moving. The 

 tongue is then thrown forward, and picks up the fly on its tip 

 and returns it to the throat. Toads live to a great age. The de- 

 velopment is much like that of the Frog, but the eggs are laid 

 in two long strings, the ova being surrounded by a gelatinous 

 substance and placed alternately. Sometimes these strings of 

 eggs reach four feet in length. They hatch out later than 

 Frogs, the larvae not maturing until August or September. 



The Natterjack can be told by having a pale line down the 

 back. Unlike the Common Toad, it is found in dry places, only 

 going to the water to breed. 



In the Ranidce or Frogs the upper jaw carries teeth. The 



