i68 OVIPAROUS QUADRUPEDS. 



lefs marked i in fome diftinfl, in others membraned. The hind legs 

 much longer than the front ; whence they do not walk, but leap : the tar- 

 Jus almoft always as long as the legs. They have no ribs, nor vertebra in 

 the neck, or at moil one or two ; their head being attached immediately 

 to the body, like that of a fifh. The young appear long under the tad- 

 pole form. 



They may be divided into three kinds: i. Thofe with long bodies 

 and heads, thin bellies, and very long legs. 2. Thofe whofe toes have 

 a fmail vifcous ball, by means of which they fix themfelves even on 

 the under furface of the moft polilhed bodies. 3. Thofe with round 

 bodies and heads, very fhort fore legs, hind legs not long j leap with dif- 

 ficulty ; fear the light, and appear only in an evenings their eyes being 

 formed fimilar to thofe of owls, &c. 



THE FROG. 



TH E figure of the Frog is well known. Its power of taking 

 large leaps is remarkably great. It is the beft fwimmer of 

 all four-footed animals ; Nature hach finely adapted its parts for 

 thofe ends, the arms being light and aflivc, the legs and thighs long, 

 and furnifhed with very flrong mufcles : muzzle ends in a point; large 

 eyes, lively, encircled with gold colour ; ears behind the eyes, covered 

 witii a membrane : noftrils near the end of the muzzle : large mouth ; 

 no teeth; tubercles, and afperities on the back. Colour, more or lefs 

 bordering on green, in fome kinds. Four toes before; five behind, thefe 

 membraned. The inner toe in all the feet feparated from the others, 

 and largeft. A vifcous humour fweats through the pores of its fkin. 

 Very little brain for its fize; a very wide fwallovv ; a ftomach feemingly 

 fmall, but capable of great diftention. The heart has but one ventricle; 

 fo that the blood circulates without alTiftance from the lungs, while under 

 water. The blood moves very (lowly, and unequally, drop by drop. 

 While young, they open and fhut their mouth and eyes, every time the 

 heart beats. The lungs refemble a number of fmall bladders joined to- 

 gether, like the cells of a honey-comb : are connected to the back by 

 mufcles, and can be diftended or exhaufted at the animal's pleafure. 



3 The 



