HERPETOLOGY OF THE GRAND DUCHY OF BADEN. 259 



2. V. aspis, L. — The existence of this species in the extreme 

 south of the Grand Duchy has at last been satisfactorily proved 

 (see ' Zoologischer Garten,' 1890, p. 265), though it had been 

 long suspected (ibid. p. 12). This isolated outpost has doubtless 

 been reached from the Swiss Jura by way of Bale, in the neigh- 

 bourhood of which town it sometimes occurs. 



In Western Germany it is cited from parts of Lothringen, 

 but its distribution there is so far not accurately determined. 



3. V. ammodytes, L. — A single specimen of this viper was 

 caught, I think, about 1830, in Southern Bavaria, and served for 

 the time to found its claims as a German species. These claims, 

 however, have been shown to be null and void.* 



Has any use been assigned to the curious little horn on 

 the head of this snake ? According to Leydig, it resembles in 

 structure the wattles of gallinaceous birds, and we might infer 

 from analogy that it served for the same purpose as those of 

 different species of lizards. Similar protuberances are found on 

 the heads of various other snakes, not the least remarkable being 

 the double projection on that of the Cerastes viper, which, to 

 judge by the shape of the head in other sand-inhabiting reptiles, . 

 would seem to be of considerable inconvenience to its owner. 

 But its accompanying advantages must more than counterbalance 

 this. Brehm suggests that these horns act as organs of touch, 

 by informing the snake of dangers " which its eye, unaccustomed 

 to the daylight, could not perceive." t They do not, however, 

 appear to be particularly sensitive. It is also improbable, in view 

 of the general adaptive tints of this species, that they should 

 serve to inspire terror into the hearts of would-be persecutors. 



Possibly they may be, as Mr. Wallace suggests of the Cobra's 

 hood, t a lawful means of warning, whereby to escape any 

 " experimental tasting" on the part of its foes, and to judge by 

 the difficulty we ourselves encounter in distinguishing poisonous 

 snakes, such a mark of recognition would no doubt prove advan- 

 tageous. Still, this would be crediting the hawks and other 

 birds which might pounce down upon it with extremely acute 

 powers of vision. 



;:: ' Leydig, ' Einheimische Schlangen,' 1883, p. 81. 

 f ' Reptiles,' p. 48G. J ' Darwinism,' p. 263. 



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