251 
had goiie on to such an extent, that though the animal when 
placed in water displayed them as usual, they were useless for 
breathing purposes, and every effort was used to regain the land. 
Friiulein von Chauvin makes the suggestive remark, that the 
gills and tail-fin seem to shrivel by an actual drying process 
through the action of tho air ; not by the true process of absorption 
by the vital processes of the animal itself. This is important as it 
shows how the first airbreathing amphibia ( Caducibra nch iata) may 
have been evolved from double breathers ( Perennibranchiala ) by a 
succession of dry seasons, that is, by purely mechanical causes. 
Further changes went on. The skin was cast several times, the 
gills disappeared altogether, and the gill clefts closed ; the dorsal 
ridge, and tail-fin vanished, and the tail became rounded ; the toes 
assumed a longer and rounder form, and were hardened with a 
horny deposit at the tips ; the eyes became larger and more promi- 
nent ; the skin lost its black slimy appearance, becoming at first 
black shot with green, and finally brownish black, with a violet 
shimmer, spotted on tho throat and belly with yellow. Thus the 
complete Amblystoma form was assumed, and with the change of 
body a change of disposition, both animals being now of an 
astonishing greediness. 
The converse of this series of experiments were made by the 
same observer. All salamanders, newts, frogs, and toads, lay eggs, 
from which gilled tadpoles are produced : but the black Alpine 
Salamander found at an elevation of more than one thousand feet, 
lacks the recpiisite pools for its aqu itic life ; and in correspondence 
with its altered surroundings, the young are born alive and fitted 
for terrestrial life, having possessed gills only in uiero, where they 
of course were useless. Von Siebold tried whether the ripe foetus 
would live in water, but was unsuccessful. Friiulein von Chauvin 
was however more skilful, and of two specimens one died ; the 
other in the course of four days cast off its large gills, developed a 
new set of an abnormal form, and lived a fish life for fifteen weeks, 
usually remaining at the bottom of the tank. The gills then 
disappeared, and the true form of SalamciHrira atra was gradually 
assumed. 
