8 
As neither of these Sirens was found to add much 
to its size, in the period of ten or eleven months, it 
would seem to follow, that the reptile is rather slow 
in attaining its full growth. It is highly probable, 
that the one which I possess (much the smallest of 
the two) is now, at least, four years old. The 
largest specimen, which seems to have nearly reached 
the maximum size of the animal in Carolina, was, in 
all probability, eight or ten years old; nay, reasoning 
on the analogy of the growth of some of the amphibia, 
most nearly allied to it ; and resting, in part, upon the 
uncommonly firm texture of the whole of the vertebral 
structure, I think we are safe in assigning to this 
individual Siren, a greater age than that which 1 
have mentioned. But do we know of any of the lar- 
vae of salamandrae which retain their branchial fins 
for several years ? I think we do not. Indeed, if I 
do not greatly mistake, in all the salamanders and 
Water- Lizards, with which we are acquainted, the 
branchiae are nearly obliterated the Jirst year of the 
animaFs life.* 
I may here observe, that the branchiae of Sirens 
* Professor Gmelin throws out a suspicion, that the Proteus 
Tritonius and P. anguinus, concerning whose precise nature he 
does not venture to hazard a decisive theory, or opinion, may be 
mere Gyrini, “ which undergo a more tardy metamorphosis” than 
their congeneres, among the amphibia, do. Systema J\faturae. Tom, 
1. Pars hi. p. 1056, The same suspicion may be hazarded in re- 
gard to the Sirens. But, really, it appears to me, that it was moi’e 
tinily philosophical, even in the time of Laurenti (1768), to con- 
jecture, that the Protei were perfect animals, than to assert, as has 
since been frequently done, that they ai’e aiiimalia larvata.^ Nor 
do I think there was any thing peculiarly rash or audacious in the 
oljservation of the Vienna physician, “ that those who contend, that 
the Proteus anguinus is a mere, gyrinus, should show the animal 
which proceeds from /;;: otherwise, that he would adhei’e to his 
own opinion,” See Schneider’s Historia, 8cc. Fasc. i. p. 45. 
