HERPETOLOGY OF THE GRAND DUCHY OE BADEN. 183 



of several Lamenis viridiflavas and Coelopeltis lacertina which fre- 

 quented the same spot. Examples of such positively protective 

 coloration will occur to everyone who has paid attention to this 

 species in its native haunts, though it is not, as a rule, so 

 pronounced as in the instances given. Thus, more recently, in 

 the Lipari Islands I have come across races of this species on 

 black lava, or white pumice partially covered with vegetation, 

 in consequence of which the adaptation was not so complete, 

 though still recognisable. It has also struck me that the very 

 green colour of L. muralis in the fields of Lombardy may be 

 thus accounted for. 



The class comprising most varieties of L. muralis (from this 

 point of view) contains those whose colour is not adapted to any 

 special environment. It is protective only in a negative sense, 

 inasmuch as a still brighter coloration would render the lizards 

 too conspicuous.* Under this denomination may be included 

 nearly all varieties of this species. 



There is yet a third class containing some island forms of 

 this species (L. filfolensis, &c), whose colour cannot, I think, be 

 called protective in any sense of the word. Owing to the absence 

 of enemies, the equilibrium between competing species is in 

 these localities no longer preserved, and, under such exceptionally 

 favourable circumstances, these remarkable divergent forms have 

 been developed. That they should resemble each other to a 

 certain extent is not more than we should expect, considering 

 their common origin, and the natural tendency to analogous 

 variability under similar conditions, while it is noticeable that 

 the main points of difference are such as exist between the 

 secondary sexual characters. There are many islets in the 

 Mediterranean on which the lizards are of necessity protectively 

 coloured, being few in number, and, if possible, more shy than on 

 the mainland, but this is due to the number of enemies, chiefly 

 Kestrels, of which the lizards must constitute the sole food. 

 But the most divergent island forms are again bound to those of 

 the second denomination by a series of transitional types, so that 



* The colours of European Lacertidce can hardly be termed aggressive. 

 For capturing their prey they are dependent alone on their agility, and 

 though certain forms of coloration may " enable them to creep upon their 

 prey" more easily, these have been developed solely, I venture to think, as 

 a protection from enemies. 



