252 FROGS, TOADS, AND NEWT, 1 ', [CH. VIII 



capturing the prey. This remarkable movement of the 

 tongue is the result partly of direct muscular action and 

 partly of injection of fluid into the lingual lymphatics. 

 According to Hartog 1 the action is fcommenced by the 

 petrohyoid and geniohyoid muscles lifting the hyoid 

 cartilage and bringing it forward; the genio-glossal muscle, 

 running from the chin into thj tongue, and stylo-glossal 

 muscle begin the dilation by shortening and widening 

 the cavity of the tongue, but the chief muscle concerned 

 in projection is the mylohyoid, which, running across the 

 floor of the mouth, by forcible contraction drives lymph 

 into the tongue. In retraction the hyoglossus, from the 

 bony part of the head to the tongue, and the intrinsic 

 lingual muscles draw the tongue back into the mouth ; the 

 sterno- and omo-hyoids, passing back to the shoulder girdle, 

 pull back the attachments of the tongue to the hyoid 

 cartilage, and closure of the mouth forces the tongue 

 against the palate, and presses out the rest of the lymph. 

 A small animal, such as a beetle, when seized by the 

 tongue is thus conveyed straight to the top of the gullet 

 and swallowed without being touched by the teeth. Larger 

 animals such as worms and slugs are seized between the 

 jaws and swallowed more gradually. It is in dealing with 

 relatively large and slippery prey of this character that 

 the teeth are of importance. They are carried upon the 

 premaxillaB and maxilla, bordering the upper jaw, and 

 in two patches upon the vomers in the roof of the mouth ; 

 the mandible, or lower jaw, is edentulous. All the teeth 

 slope inwards. Their function is clearly that of holding 

 1 C. JR. Acad. Set. Paris, t. 132, and Ann. Mag. Nat. Hist. (9) vu. 



