ALLIED TO LACIiKTA ]\iriULIS. ]5 



villi tl.c most piiiiiitivc: («) a liyht veiteLrul stripe, [b) a dark vertebral stripe, 

 {(■) no vertcLral btripe or series of spots. Ea'cli of these leads independently to the 

 ccellatcd, spotted, reticulated, or cross-barred types. 



In the evolution of colours, leaving out of consideration the bright yellow, red, or 

 blue tails which form part of the juvenile livery of some Lizards *, the vivid hues 

 (yellow, green, blue, or red) appear first as a seasonal character of the breeding male, 

 before persisting throughout life ; they are afterwards passed on to the female. In all 

 Lizards the young at birth arc black and white, grey, or greyish brown (blackish in 

 L. vivipara). In L. CKjilis the typical form retains the grey or brown colour, the 

 males being green on the sides during the spring and early summer only ; but very 

 exceptionally the green may extend to the upper surface in males, and may appear 

 on the sides in females; in the vars. chersoiieiisia and eaigiia, some specimens of which 

 are further advanced in the direction of L. vin'dis, males are sometimes, and females 

 less frequently, green all over, and this colour is retained beyond the breeding-season. 

 In L. viridis both sexes are usually green when adult, and at all seasons ; but in 

 some localities the females retain throughout life the brown colour of the young. 

 Blue over the throat and the sides of the head, or as spots or ocelli on the flanks, 

 occurs more frequently in males than in females, and in some forms is the exclusive 

 endowment of the former. Green may be replaced by bright yellow (upper parts of 

 L. ocellata, L. mura/is, var. nujriventris, lower parts of i. viridis). Eed, as an intensi- 

 fication of yellow, passing through orange, adorns the lower parts of many Lizards, 

 especially during the breeding-season, or, derived from reddish brown, the back of 

 certain specimens of Z. cujUis (var. rubra), appearing in the same order as does the 

 green ; or it may accompany the blue as part of the nuptial garb in the males 

 {L. peloponneduca). The importance of colour for defining species, or even varieties, 

 has been much exaggerated by most authors. 



1 have now explained the principles which have guided me in my attempt to trace 

 the derivation of forms in the genus Lacerta. They are entirely at variance with those 

 recently advocated by Prof. v. Mehely. I submit them to the consideration of future 

 investigators, and now pass on to the descriptions of the species, with comments on 

 their relationships. 



* Lacertida;, Teiida;. Sciiicida?, Agnniidoc. As regards tlio coloration of the rest of the bodv, I caunot 

 call to mind a single instance in Lizards in which the young is more brightly coloured than the adult, though 

 in many cases the markings are more sharply defined or the pat terns more elegant. This is remarkable, 

 considering that the reverse is the case in many Snakes, Tortoises, and Eatrachians. 



