40^ Observatimis on the Natural H\st<yry 
a skilful anatomist, and not less estimable for his learning than 
for the suavity of his manners. There is reason to believe, 
that, when at their full growth, they reach to 14 inches or 
even more. That described by Schreibers in 1801 was 13 
inches in length. With regard to age, there is reason to think 
they are pretty long lived ; for the Archduke John of Austria, 
a zealous cultivator and liberal patron of natural science, kept, 
in a subterranean grotto, constructed for the purpose, several of 
these animals, one of which lived eight years, and acquired a 
size greater than ordinary. 
When viewed alive, and in water, the body of the proteus 
appears at first of a cylindrical form, but when more attentively 
surveyed, it is seen to be somewhat flattened on the sides, espe- 
cially towards the tail, which, beyond the lower limbs, is redu- 
ced at length to the shape of a spatula. The back and head 
of the animal are of a whitish-red colour, which, on the sides 
and tail, inclines to violet. The belly, on the contrary, is 
white, though even there, in the region of the liver, it has a 
bluish cast, like that of the human veins, seen through a very 
fine and delicate skin. An illustrious writer, ^ho had observ- 
ed a proteus only after having been kept in spirits, has describ- 
ed the skin as very opaque ; but we, say the authors, who have 
seen many protei alive, can with confidence affirm, that so far 
from being opaque, the skin of these animals is, almost beyond 
belief, transparent, — to such a degree, indeed, that the colours 
or tints, as painters express it, are so very diaphanous, that, to 
represent it by words, is quite impossible, and by the pencil 
sufficiently difficult. Those unacquainted with painting may 
doubt our assertion, but those the least instructed in that art, 
and v/ho know by experience how difficult it is to imitate a 
diaphanous tint, will remain painfully convinced of this, when 
told that the diaphanity of the tints of the Proteus Anguinus 
(be the human skin as white, morbid, and subtile as you please) 
exceeds by far that of the colours of the human body. But 
the flesh-colour of this animal in course of time changes; and 
this happens more or less quickly, according as he is more or 
less exposed to the light. From whitish-red the skin passes by 
The authors employ the old French measures. 
