540 



REPTILIA. 



that, were the creature to preserve this form throughout its life, the 

 naturalist would scarcely hesitate in classing it with fishes properly 

 so called. 



When first hatched (fig. 239, B),* it presents the same fish-like 



Fig. 239. 



body, and rows 

 itself through 

 the water by 

 the lateral 

 movements of 

 the caudal fin. 

 The only ap- 

 pearance of legs 

 as yet visible 

 consists in two 

 minute tuber- j 



cles, which C 



seem to be sprouting out from the skin immediately behind the 

 branchial tufts, and which are, in fact, the first buddings of ante- 

 rior extremities. Nevertheless, to compensate to a certain extent 

 for this total want of those prehensile limbs which afterwards 

 become developed, two supernumerary organs are provisionally 

 furnished, in the shape of two minute claspers, seen in the figure, 

 situated on each side of the mouth ; by means of these the little 

 being holds on to the subaquatic leaves, and thus prevents itself 

 from being washed away by the slightest current. 



Twelve days after issuing from the egg, the two fore-legs, which 

 at first resembled two little nipples, have become much elongated, 

 and are divided at their extremity into two or three rudiments of 

 fingers (fig. 239, c). The eyes, which were before scarcely visi- 

 ble, and covered by a membrane, distinctly appear. The branchiae, 

 at first simple, are divided into fringes, wherein red blood now cir- 

 culates ; the mouth has grown very large, and the whole body is so 

 transparent as to reveal the position of the viscera within. Its 

 activity is likewise much increased ; it swims with rapidity, and 

 darts upon minute aquatic insects, which it seizes and devours. 



About the twenty-second day (fig. 240, u) the Tadpole, for 

 the first time, begins to emit air from its mouth ; showing that 

 the lungs have begun to be developed. The branchiae are still 

 large. The fingers upon the fore-legs are completely formed ; 



* Vide Rusconi, Amours des Salamandres Aquatiques, et developpement du Tetard de 

 ces Salamandres depuisl'ceuf jusqu'a 1'animal parfait. 4to. Milan. 1821. 



