12 
in bestowing upon the American animal, the two- 
fold respiratory system of lungs and gills ? 
I am far from imagining, that the views of Nature, 
in this complex and admirable fabric of the Siren, 
arc fully understood. Yet, I cannot but flatter my- 
self, that my experiments have put us in possession 
of something like a clue to the attainment of the 
truth ; and I do not doubt, that future and more va- 
ried experiments and inquiries will completely un- 
fold to us, the wise designs of Nature in furnishing 
the Siren (and its congeneres Proteus anguinus, &c.) 
with both branchiae and pulmonary lungs. 
But this interesting portion of the Siren’s history 
cannot be completely and satisfactorily understood, 
until skilful naturalists, residing in the countries of 
wiiich this animal is a native, shall examine, with 
attention, its manners and habits ; until it shall be 
ascertained, what proportion of its life the Siren 
passes in the water, and what proportion on the dry 
ground, or upon and in muddy situations, Mhere it 
cannot have the advantage of a sufiicient quantity of 
water to admit of its swimming, and of using its 
gills; whether (as I have already intimated there are 
some reasons to believe) it performs migrations from 
one water to another, over the mud or meadows, or 
even drier situations ; in what manner it passes the 
winter season ; whether, in other words, it becomes 
torpid, &c. These and similar points^, relative to 
the natural history of the Siren, must be fully ascer- 
* Among other experiments, which I have thought of, there is 
one v/hich could hardly fall to throw considerable light upon the 
pliysioiogy of the Siren I mean, the removal of one, or all, of the 
branchial appeiidagcs, by means of ligatures. 
