sm, 
Very lately I received, through the kindness of 
one of ray foreign correspondents, the two first fasci- 
culi of Historia ^mphibiorum natmalis et literaria. 
I have not yet had time to peruse the whole of the 
work ; but, having looked, with attention, into va- 
rious parts of it, I do not hesitate to consider it as one 
of the more important works on Zoological science, 
that have appeared for many years. In return 
for the real satisfaction which your History has af- 
forded me, 1 beg leave to call your attention to a few 
scattered facts and observations, relative to one of 
the most interesting subjects of investigation in the 
whole science of Amphibiology. 
I cannot adopt your opinion, that the Siren de- 
scribed by Mr. Ellis, Mr. John Hunter, and other 
naturalists, is nothing but the cordylus (or larva) of 
a species of Lacerta, or Salamandra. I have 
lately paid particular attention to the history and 
Structure of one of the Carolina species of Siren, and 
I am now thoroughly convinced, that this singular 
Amphibious Bipes,” concerning which so much 
has been written and conjectured, is, in reality, a 
finished animal ; which never looses its branches or 
gills, but continues to respire by means of them, as 
well as by lungs, during the whole period of its life. 
I am far from flattering myself, that you will be- 
come an easy convert to my opinion on this subject. 
Yet, I cannot doubt, that the facts and observations 
which I am to communicate to you, will lead you to 
review, with attention, that part of your history 
1 
