AMPHIBIANS. 95 



stages may be observed : (1) tte round egg becomes 

 elongated; (2) furrows appear; (3) head, tail, and dingers or 

 claspers partly distinguisliable ; (4) branchise may be seen 

 on each side of head ; (5) a little movement observable ; 

 (6) the nostrils can be detected; (7) branchise more distinct 

 and lobed, and in which the circulation of the blood may be 

 watched under the microscope (c) ; (8) jerkings from a curved 

 into an almost straight position (d) until the envelope is 

 broien and the tadpole is free (e and /). The branchise (g) 

 now grow until they arrive at their full size (h), and then 

 they begin to decrease, soon becoming altogether hidden by 

 the operculum, and after being absorbed are replaced by 

 lungs. The little animal begins to take the true tadpole 

 shape (i) ; the eyes are more distinct, and the mouth 

 appears at the extremity of the head. After a time, short 

 or long according to circumstances, the hind legs bud and 

 grow (k), and these are followed by the forelegs (l). When 

 all the legs have appeared, the tail, beginning at the tip, 

 becomes gradually absorbed. It used to be gravely asserted 

 that the tails fell off. The creature is now able and willing 

 to leave the water and live almost entirely upon land. Young 

 tadpoles at first feed upon vegetable matter and afterwards 

 upon animal. They are capital scavengers in the aquarium, 

 living there for many months in the tadpole state. I had one 

 in the middle of September which, I think, was hatched 

 early in March, and it had not then obtained its fore-legs. In 

 October, I have caught tadpoles with no legs developed, and 

 sometimes they will live for a whole year in a tadpole con- 

 dition. This tardy development into the frog or toad is due, 

 I suppose, to an insufficiency of animal food. 



The spawn when first obtained should be placed in some 

 shallow vessel, the bottom of which is covered with well- 

 washed river sand. If a rapid development of the embryo 

 is required, the eggs must have both light and heat. As soon 

 as the tadpoles, after becoming free, have consimied that 

 portion of the spawn which they will eat, they should be 

 removed to a larger vessel, especially if their number is at all 

 great ; and when moved they should be provided, in small 



