POISONOUS SNAKES OF NORTH AMERICA. 347 



asserted with characteristic positiveness that it is "erroneous" to class 

 with venomous serpents those snakes which have the posterior teeth 

 long and channeled. However, a short time after, Prof. G. L. Duver- 

 noy, of Strasbourg-, published a no less important treatise on the sub- 

 ject.* He pointed to the yellow portion of the supramaxillary gland 

 as being structurally different from the white portion, and from Us being 

 connected with a large grooved fang by a single duct he concluded, with 

 equal assurance, that we have here before us a venom apparatus only 

 in degree differing from that of the snakes with poison ftings fixed to 

 the anterior end of the maxillary bone. His results were accepted and 

 introduced into the classification adopted in the monumental herpeto- 

 logical work of Dumeril and Bibron, the Erpetologie Generale, in 

 which the snakes with grooved posterior fangs were placed in a separate 

 group as ^'Opistofflyphsr On the other hand, Schlegel, paying no 

 attention whatever to Duveruoy, in his "Physiognomic des Serpentes," 

 maintained his standpoint, and so great was the authority of the learned 

 Leyden professor that his view was until quite recently accepted by 

 some of the most prominent systeraatists. It seems that neither side 

 ever attempted to end the dispute by direct experiments, and gradu- 

 ally the Opisto(jhjphs to many herpetologists ceased even to be "sus- 

 pected." 



About ten years ago the interest in this question was suddenly 

 revived, and as it may now be fairly regarded as a burning one, some 

 space will be devoted to a short review of several of the recent inves- 

 tigations into this theme. 



Two Italian students, M. G. Peracca and C. Deregibus, were led to 

 make special investigations into the possible venomous nature oi Mal- 

 polon lacertina { = Ccvlopeltis insignitus), a snake common about Nizza 

 and in parts of Italy. In a communication to the Academy of Medicine 

 at Turin, in May, 1883, f after first describing the grooved fangs, the 

 glands, and the duct leading to the fang, they recounted their experi- 

 ences with the snake in question: 



Their experiments were carried out with two specimens of Coelopeltis 

 {=2MpoJon), one of medium size, the other much larger; the victims 

 consisted of lizards, frogs, and toads. The snake did not bite them 

 voluntarily; it was necessary to open its mouth and to force the animal, 

 into its throat; whereupon the snake inoculated the venom, the motion 

 of the bone carrying the poison fangs being very distinctly seen on 

 account of the manner in which they were standing out from the poste- 

 rior part of the head. The act of biting lasted some moments, and 

 the snake repeated this act several times without allowing its prey to 

 escape. 



The animals were bitten in the hind limb; in the case of the frog the 

 skin had to be removed from the part to be bitten, as the irritating 



* Ann. Sci. Nat., xxvi, 1832. pp. 144-156; xxx, 1833, pp. 6-26. 



f Giornale della R. Accadeniia di Medicina di Torino, (3) xxxi, 1883, pp. 379-383. 



