148 



THE YOUNG NATURALIST. 



extremely elongated, and articulate with the two large transverse processess 

 of the sacral vertebra. These articulations cause the two protuberances 

 externally visible, and give the creature the appearance of having had its back 

 broken. The vertebras behind the sacrum coalesce and form the urostyle, the 

 skeletal representative of the tail of the tadpole. Erogs and toads have four 

 digits on each of the forehands, the thumbs being rudimentary, on each 

 hind-leg there are five digits, all without nails. Our toads are destitute of 

 teeth, whilst the frogs possess teeth, both on the upper jaw and vomers, thus 

 enabling them to feed with more rapidity and greater certainty. In these 

 creatures the tongue is of great importance in catching food. It is soft and 

 fleshy, and of peculiar construction ; instead of being free in front, as in the 

 higher animals, it is fixed in front and free behind. When at rest the tongue 

 lies on the floor of the mouth, but when extended in use, the point comes 

 upwards and forward, and reaches some 1| inches beyond the mouth; the 

 movement being exceedingly rapid. The tongue of the toad is rounded at 

 the tip, whilst that of the frog has at either side a small fleshy protuberance, 

 and in both species the tip is supplied with a viscid fluid to which their food 

 adheres. 



The covering of the ear is visible, and is represented by a circular patch, 

 differing in colour from the surrounding skin. Both frogs and toads are 

 quick of hearing, perceiving the faintest sound, even that made by a cater- 

 pillar moving on the ground behind them, and I have also noticed that they 

 can locate the sound with great accuracy. The most beautiful organ 

 possessed by these creatures is undoubtedly the eye, which has an intense 

 lustre, the pupil being black, surrounded with a gold ring. 



To see a frog swallow its food, is to be highly amused, or equally disgusted, 

 as the remarkable manner in which the eyes seem to disappear into the head 

 gives it a most extraordinary appearance. This power of withdrawing the 

 eyes is of great value, as their ordinary elevated position, which enables them 

 to see in almost any direction, at the same time exposes them to considerable 

 danger, more especially when crawling into crevices for shelter, or to evade a 

 passing foe. 



Of the 800 species of tailless Batrachians (Ecaudata) we in Britain possess 

 four; and. these belong to two families viz., Eanidse and Bufonidse. 



Before giving a detailed description of these four species, it will be as well 

 to put in as concise a form as possible, their most striking characteristics. 



