18 THE ZOOLOGIST. 



Worms ; hence I must consider my not meeting with it there 

 as accidental : at Oberstein, on the river Nahe, celebrated for 

 its agate industry, it was likewise not to be seen. This latter 

 fact may help to support Mr. Geisen-Heyner's * supposition that 

 it does not ascend the river beyond Minister. 



The L. viridis of the Kaiser stuhl, though frequently of a 

 bluish tinge about the head and neck, is not of the true " mento- 

 carulea" (Bonap.) variety, as it is found in parts of the Tyrol, 

 Italy, &c. With typical individuals of this variety the lateral 

 and anterior portions of the head, as well as the lower jaw, are 

 often of a vivid green colour, whereas with specimens from the 

 Kaiserstuhl it is precisely ^these parts which display the most 

 intense blue, the throat itself being seldom thus marked. It may 

 therefore be assumed that the latter are tending to attain this 

 feature characteristic of the true mento-carulea, though as yet 

 they have not arrived at its typical development ; and I should 

 regard the green colour above referred to as the latest modification 

 in this line of ornamentation, thus, that the blue has gradually 

 concentrated itself on the throat, and that the head, by way of 

 additional contrast, has re-assumed the original green colour. 



Similar instances, illustrating a sort of reciprocal converti- 

 bility of the colours blue and green, when employed for mere 

 " decorative" purposes, are exhibited by some forms of L. muralis 

 — compare var. ccernleo-ocellata : viridi-ocellata — and other rep- 

 tiles ; sometimes the blue seems to have the priority, acquiring 

 only by degrees an iridescent greenish lustre, which in its turn 

 may become so permanent as to efface the original blue ; in other 

 cases the latter colour appears of more recent origin. It is notice- 

 able that the same colours alternate in an analogous manner with 

 some birds. 



Even comparatively young individuals from the Kaiserstuhl 

 are thus marked, a circumstance which no doubt favours the 

 transmission of this character from the male to the female. 

 There seems to be no difficulty in assuming such a trans- 

 mission to have taken place, in view of the fact that many 

 secondary sexual characters peculiar to the one are often 

 inherited by both sexes, and more readily if they occur at an 

 early age ; and in the instance of colour, which is most easily 

 modified and transmitted, many ornaments confined to the male 



■ \\ irbeltierfauna von Kreuznaoh, 1 1888, 



