THE NEWTS 



453 



In about two days his eyes become 

 prominent owing to the appearance of a 

 copper-coloured iris, and the upper black 

 line is more easily distinguishable from 

 the lower. 



I have mentioned that the newt tad- 

 pole sinks on emergence from the egg, 

 and I have little doubt that he 

 naturally commences his free exist- 

 ence as a ground - feeder, sucking 

 what suits hun out of the ooze, and 

 protected by his dark coloration 

 until his tail becomes a serviceable 

 swimming organ. One may often 

 see very small ne\\'t tadpoles wriggle 

 upwards in an aquarium, with much 

 the same motion as a rising loach, 

 and then fall back as if exhausted. 



A fortnight after hatching, the 

 newt tadpole has doubled in size, 

 and, owing to the de\-elopment of a 

 transparent and shapely tail, which 

 forms the greater portion of his 

 length, is white rather than black. 

 He now commences free swimming, 

 and so transparent is he as a whole 

 that only his eyes and the contents 

 of his stomach distinguish him from 

 his equally transparent surroundings. 

 This transparency is evidently of a 

 protective character, and he does 

 well to remain on the bottom until 

 it is acquired. 



Free swimming seems to mean a 

 change of diet ; in place of a sucker 

 he develops a mouth, and, I fancy, 

 feeds on animalculae, for he is con- 

 tinually hawking through the water, 

 and when he comes to anchor on the 

 vegetation, appears, unlike the frog 

 and toad tadpoles, to be merely resting. 

 Another interesting distinction from the 

 latter is afforded by the order in which 

 his limbs appear. 



In newt tadpoles the front legs are the 

 first to develop. Commencing as two 

 small buds, they gradually lengthen into 

 twigs, branch at the ends into fingers — 

 first three and then four — and finally 

 form remarkably skinny limbs, which are 

 always held flexed at the middle joints. 

 The adult newt swims entirely with his 

 tail, and the strength of this member natur- 

 ally increases as the newt tadpole grows. 

 It is an evident advantage to have the 

 first balancing limbs forward. In the case 



58 



of frog and toad tadpoles the contrary 

 happens. The tail gradually loses power, 

 and the early growth of swimming hind- 

 legs compensates for the loss. 



Simultaneously with the growth of his 

 hmbs one can occasionally detect small 

 bubbles of air from the newt tadpole's 



Side view (.^ ) and front view (/j) of half-developed Tadpoles 

 of the Smooth and Great Warty Newts. The Smooth 

 Newt Tadpole is to the right in each case, and the feathery 

 gills and developing limbs can be distinguished. 



mouth, which show that his lungs are 

 coming into being. From this point his gills 

 begin to atrophy and he becomes less and 

 less a fish and more and more an am}:)hibian. 

 His body shortens up. his limbs thicken, 

 his skin loses its transparency, his gills 

 disappear, and his gill-openings close. In 

 three or four months, if all goes well with 

 him, he is a perfected air-breathing newt. 

 He now leaves the water, and it is prac- 

 tically certain that he does not return to 

 it until his third or fourth year, when he 

 is mature. As to what he does during the 

 warm months which intervene, and as 

 to how he lives, practically nothing is 

 known, and much careful investigation is 



