HERPETOLOGY OF THE GRAND DUCHY OP BADEN. 139 



grinde, Wildsee), as well as further south, in the neighbourhood 

 of Freiburg (Feldberg, &c.) ; further eastwards its range extends, 

 I believe, as far as Donaueschingen. On the Kaiserstuhl, and in 

 all districts where the vine is cultivated, this species is replaced 

 by L. agilis, which shows less antipathy for human proximity, 

 and it may be worth noticing that in Baden it does not seem to 

 frequent moist low-lying districts as in other parts of Germany 

 and elsewhere. In the hilly country of the Southern Palatinate 

 this species is also found, at least if I may rely on the statement 

 of an exceptionally intelligent peasant, who surprised me by 

 describing accurately all the native reptiles, and, most of all, by 

 designating L. muralis as the " Italian " lizard. 



In point of size this species is smaller than L. agilis, and of 

 more delicate build. The extreme length may be put down to 

 17 cm., very few, even full-grown specimens, attaining more 

 than 16 cm. 



Being found at altitudes where snow lies for six months in 

 the year, this lizard must necessarily be of very hardy consti- 

 tution, and in the Schwarzwald it may be seen up to the end of 

 October on ground already covered with hoar frost. It often 

 emerges as early as March. The dark coloration sometimes 

 exhibited by this species has led to some speculation as to its 

 probable cause, and a good deal of evidence has been adduced to 

 show that both here and with Anguis fragilis this "melanism" 

 has resulted from moisture of the surroundings. But the effects 

 of this are easily over-estimated in dealing with the number of 

 similar cases for which no explanation has hitherto been 

 attempted. Keferring to L. nigra, Wolf, it has also been 

 suggested that its dark colour is in some manner connected with 

 the " high altitudes " at which this lizard is often found, while 

 it remains obscure what "moisture" and "altitudes" should 

 have in common in order to be able to influence the colour of 

 this and other species in an analogous manner.* In the Alps 



* Unless I am mistaken, two distinct melanistic varieties of the Rattle- 

 snake have been discovered in N. America; one, Crotalophorus Kirtlandi, 

 inhabiting swampy districts, the other confined to portions of the White 

 Mountains. Some cases might be quoted to show that a sudden change to 

 moisture has been temporarily followed by a general darkening of the ground- 

 colour ; on the other hand, a peculiarly light coloration has been attributed 

 to the same cause. 



M 2 



