CH. VIII] FROGS, TOADS, AND NEWTS 251 



active use as it crawls up the bank on to the land again. 

 When the anima is swimming slowly the front limbs do 

 make feeble strokes. During rapid swimming however 

 they are kept closeiy pressed to the sides of the body and 

 extended straight backwards. The common toad on the 

 other hand generally swims holding the front limbs flexed 

 at the elbow with the hands beside the head, and the digits 

 pointing forward. If severely pressed he will dive and 

 throw the front limbs into the attitude adopted by the 

 frog. But the natterjack toad, which is a more thoroughly 

 terrestrial animal, cannot by any provocation be induced 

 to put the front limbs back against the sides of the body. 

 With comparatively weak strokes of the hind legs this 

 animal paddles along on or very near to the surface of the 

 water with the hands in contact with the sides of the face. 

 Food and Digestion. The food consists of snails, slugs, 

 beetles, earwigs, dipterous flies, worms, and other small 

 invertebrate animals. The prey is seized by means of the 

 tongue. This is a bluntly bilobed muscular organ attached 

 anteriorly to the floor of the mouth, its bifid free end being 

 directed down the throat. In taking food the tongue is 

 flicked out of the mouth and back again with extraordinary 

 rapidity : its free end is thrown by a somersault an inch 

 or more in advance of the tip of the jaw, and whipped 

 back again to the pharynx, carrying the prey with it. As 

 the tongue is being projected it wipes from the roof of the 

 mouth the secretion of the intermaxillary glands a mass 

 of convoluted tubes between the premaxillae and opening on 

 the front part of the palate. This secretion is extremely 

 adhesive mucus, and forms a very effective instrument in 



