366 METAZOAN PHYLA 



moist earth and coils her body about them. When hatched the larvae 

 are nearly mature. An alpine newt which occurs in mountain lakes in 

 Europe brings forth its young alive, the tadpole stage being undergone 

 and metamorphosis taking place in the uterus of the mother. 



394. Salientia. — The tailless Amphibia are, generally speaking, 

 divided into two types, those without a tongue and those with one. 

 Among those without a tongue is the curious Surinam toad. This is an 

 aquatic toad with very large hind feet and a short, broad head. During 

 pairing the oviduct is protruded through the cloaca and passed forward 

 between the back of the female and the abdomen of the male. As the 

 eggs are passed from the oviduct, they are fertilized and spread over 

 the back of the female, to the surface of which they become firmly 

 adherent. Gradually they sink into pockets in the skin, each pocket 

 having a sort of lid. In these pockets the young develop until they 

 are prepared for independent life. The male of the European obstetrical 

 frog carries strings of eggs on his hind legs and releases the tadpoles in 

 water when they are ready to hatch. 



The tongued forms include both frogs and toads. There is no sharp 

 distinction between the two but usually a soft-skinned, partly aquatic 

 type is known as a frog (Fig. 254G), and a harder-skinned, more terrestrial 

 one as a toad. The true toads also have no teeth on either jaw. They 

 have a harsh, warty skin, ridges on the head, and a kidney-shaped raised 

 area behind the head on each side known as the parotoid gland (Fig. 250). 

 When disturbed, toads frequently pass water from the bladder, and the 

 superstition is widely spread to the effect that the handling of a toad 

 will cause warts. They are nocturnal in habits, feeding upon insects, 

 worms, and snails. Their skins contain glands which produce noxious 

 secretions and they are therefore rarely eaten by other animals. 



The frogs have a body which is somewhat spindle-shaped, pointed 

 anteriorly, and rounded posteriorly. The forelegs are weak and the 

 toes only slightly webbed; but the hind ones are long and strongly 

 muscled, with long, fully webbed toes, fitting them for leaping and 

 swimming. On superficial examination the male of common frogs 

 may be distinguished from the female by the greater thickness of the 

 inmost digit of the forefoot. The metamerism of the body wall is 

 greatly obscured, this being due in part to the shortness and compactness 

 of the body and in part to the development of muscles connecting the 

 limbs to the trunk. 



Just in front of each gonad is a yellowish fat body which in the frog 

 consists of a series of finger-like lobes; it seems to be a fat-storage organ. 

 Above the anterior end of the cloaca is the spleen in which worn-out 

 red blood corpuscles are destroyed and in which white corpuscles are 

 formed. There are also several glands falling under the general designa- 

 tion of ductless glands, the secretions of which are known as internal 



