382 THE ZOOLOGIST. 



northern Lacerta muralis is less susceptible to the sound of 

 music than the Italian race — a statement which I can bear out ; 

 the Sardinian Tree-frog is credited by another writer with a more 

 " angry, passionate disposition " than the ordinary form, &c. 



All such observations would be comparatively valueless were 

 it not for the fact that definite tendencies, or directions of 

 variation in habits and temperament, are characteristic of certain 

 species. For the effects would otherwise, as with variability in 

 size, or structure, or colour, be "swamped" or neutralised. As 

 it is, we can understand how, under circumstances perpetually 

 changing from an economical and physical point of view, a 

 differentiation in habits may often prove beneficial, if not 

 essential, to the welfare of some members of a community ; and 

 this, in its turn, may entail a modification of parts sufficient to 

 warrant the creation of a 'Nova species.' 



5. Coronella austriaca, Laur. — The Smooth Snake is not 

 found, I believe, in the actual Ehine-valley, but is sufficiently 

 common on the hills, chiefly in old disused sandstone quarries. 

 Five or six can be obtained in an afternoon without much 

 trouble. 



The extreme length of 80 centimetres, often cited, seems a 

 trifle exaggerated, as the Baden specimens, which are by far the 

 largest I have seen, seldom exceed 65 cm. The parallel rows of 

 spots on the back are preserved intact only by the young ; whereas 

 with increasing age they tend to coalesce into longitudinal bars, 

 or to form a cross-striped figure, though neither of these 

 patterns are very marked. At other times they become in- 

 distinct, in which case the two lateral lines are the first to fade, 

 leaving often only the dark streak through the eye as vestiges. 

 The markings always remain most pronounced in the anterior 

 portions, and the head generally retains to the last the three 

 characteristic transverse stripes. The lower surfaces are reddish 

 with the young, as with English specimens, and darken gradually 

 to a uniform brown with opalescent lustre. The throat remains 

 throughout of a lighter tint. Along the edge of the ventral 

 plates two scarcely perceptible lines of lighter colouring may 

 sometimes, as with Elaphis fiavescem, be seen. 



According to Prof. Niisslin, a bicephalous individual of this 

 species was caught in 1881 not far from Karlsruhe, and kept 

 alive for some time. This peculiarity does not seem to be as 



