121 
and Structure of the Aquatic Salamander, 
forces his way out by tearing it : If it be now lightly touched, 
it makes lateral movements with its trunk and tail, and is thus en- 
abled to swim ; but in a mode different from that which it after- 
wards employs. Its movements indeed, at this period, may be 
said to be purely automatic : it strikes sometimes against a leaf, 
sometimes against the sides of the vessel, and as soon as it does 
this, it attaches itself to the body struck, and remains suspend- 
ed, by means of its two hooks, the extremities of which are cover- 
ed with a viscous matter. One might imagine that the young 
salamander sleeps continually at this period ; for if the vessel be 
slightly shaken, its body oscillates with the movements of the 
water, just as any inanimate body would do. It now passes some 
hours without moving : Afterwards, without any evident exter- 
nal cause, it makes some lateral movements with its tail ; swims 
in its own manner ; and reattaching itself anew to some other 
leaf, it continues to sleep, or remains in absolute repose for half a 
day or more. If, while making these lateral movements, it meets 
with no substance to which it can attach itself, it falls then to the 
bottom of the water, where it continues in repose, lying some- 
times on its side, sometimeson its belly. Its eyes are scarcely as yet 
designed ; they form two prominences on the sides of the head. Its 
mouth is so slightly traced that it requires attention in the observer 
to perceive it ; it is indicated only by a very slight transverse de- 
pression, situated beneath the head, and between the two promi- 
nences formed by the eyes, and in the middle of the space be- 
tween the anterior border of the head, and the origin of the 
neck. Its fore-paws, protruding like two buds, begin to separ- 
ate from the gills ; these gills are gradually furnished with small 
leaflets. At this period, the life of the salamander may be con- 
sidered purely organic . 
In Fig. a, the same salamander is seen from below with the 
aid of the microscope ; b 5, the two prominences formed by the 
globes of the eyes, between which is the slight depression 
which becomes afterwards the mouth ; c , the hook of the right 
side ; d, the gills of the same side ; e, the rudiment of the fore 
paw of the same side ;f the same animal seen in profile ; g, the 
same viewed from above. 
18^/i May . — The same animal, of its natural size, seen from 
above, exhibiting the changes in the external form of the 
