Animals called) by Linnaeus, Amphibia . 31 
Linnaeus’s ideas about them were; nor can I better prove 
the want of information on this fubjed, than by obferving 
that, erroneous as the ideas of Linnaeus were, no one, that 
I know of, has yet attempted to futnifli more corred ones. 
Linnaeus thought the fangs might be diftinguilhed by their 
mobility ; this, at leaft, may be fairly inferred, from his never 
mentioning them in the Mufeum Regis, without adding the 
epithet mobilia , except in one inftance (the Coluber auli- 
cus) ; and, in that very inftance, the want of mobility in 
the fuppofed fangs appears evidently to raife doubts in his 
mind, whether they are really fangs or note His words 
are, “ Dentes , five tela , duo , rigida , parva , non mobilia 
Thefe doubts, refpeding the above-mentioned fpecies, I am 
not able to remove, as I am not fure that I have ever feen 
it But with regard to mobility, confidered in general as a 
charader of venomous fangs, I muft aflert, not only that I 
have never found it fq, but alfo, that I have never been able to 
difcover in them any thing which I thought could properly be 
called mobility. I have, indeed, fometimes found fome of 
them loofe in their fockets ; but then I have found others, in 
the fame fpecimen, quite fixed. The fame thing was ob- 
ferved both by Dr. Nicholes +> and by the Abbe Fontana j, 
in the common Viper, even during life. The loofe fangs may 
be fuch as have not yet been firmly fixed in their locket, or 
they may have been loofened by fome accident : for I fufped 
that the fangs may be at any time loofened, and even difplaced, 
by a fmall degree of violence ; and that, perhaps, may be one 
I have feen one, which agreed pretty well with LinnJLUs’s description ; if 
that was really his fpecies, it- is not venomous. 
f Appendix to Dr. Mead’s Account of the Viper. 
% Fontana, Traite fur le Veiiin de la Vipere, chap. I ft and 2d. 
reafon > 
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