SERPENTS. 315 



A general rule for the determination of the ex- 

 istence or non-existence of these organs in any 

 species of Serpent is proposed in a paper relative 

 to the Amphibia by Dr. Gray, and published in 

 the Philosophical Transactions for the year 1788. 

 The fangs, according to Dr. Gray, may be dis- 

 tinguished with great ease, and, as he believes 

 also, with great certainty, by the following sim- 

 ple method. When it is discovered that there is 

 something like teeth in the anterior and exterior 

 part of the upper jaw, which situation he considers 

 as the only one in which venomous fangs are ever 

 found, let a pin or other hard body be drawn from 

 that part of the jaw to the angle of the mouth ; 

 (which operation may, for greater certainty, be 

 tried on each side). If no more teeth be felt in 

 that line, it may, he thinks, be fairly concluded 

 that those first discovered are fangs, and that the 

 serpent is consequently venomous : if, on the con- 

 trary, the teeth first discovered be observed not 

 to stand alone, but to be only a part of a complete 

 row, it may as certainly be concluded that the 

 serpent is not venomous. This rule, however, 

 like most others, may have its exceptions, and 

 perhaps the most legitimate test of real fangs in 

 a serpent is their tubular structure, which may 

 always be easily detected by the assistance of a 

 proper magnifier. It is to be observed, that all ser- 

 pents, whether poisonous or not, have besides the 

 teeth (whether fangs or simple teeth), in the sides 

 of the upper jaw, two additional or interior rows, 

 which are generally much smaller than the rest, 



