1.6 Nelson Annandale — 2Vie Lizards of the Andamans. [SuppU. 



would suggest that it too may be carried from island to island) are house- 

 lizards, and as such of no importance in considering questions of geo- 

 graphical distribution. They may very well have been introduced in. 

 the nineteenth century. As regards P. homalocephalum, a curious fact 

 in its life history may have had an influence on its dispersal ; I mean 

 the long period spent in the egg. An observation by F. H. Bauer 

 (quoted by Gadow in Amphibia and Reptiles, -p. 512) shows that this 

 period may last for five months, and from eggs which I have examined 

 in the Malay Peninsula I am prepared to conclude that this case was 

 normal. It is obvious that an egg with a hard shell, to some extent 

 impermeable to liquids, can endure conditions which would be fatal to 

 a delicate young lizard. Boats have been carried out from the coast of 

 Malaya to the Andamans in very much less than five weeks, and logs of 

 wood must frequently come by the same route. P. homalocephalum 

 lays but two eggs at a time ; they adhere to leaves and tree-trunks. It is 

 essentially a jungle species, but Flower has taken a specimen of the 

 closely allied P. horsfieldii on a wooden post in the Botanical Grardens 

 at Penang ( P. Z. S. 1896, p. 868), showing that it may desert the 

 jungle occasionally for human erections in the immediate neighbourhood. 



Thus, of the nine Geckos recorded from the Andamans, the presence 

 of five, possibly six, can be accounted for without assuming that they 

 have been in the islands for any long period. The remining three are 

 peculiar to the archipelago (including Narcondani). None of these 

 have been recorded from the Nicobars ; but one is closely related to forms 

 on the nearest mainland, a second has Malabar afiinities, while the third 

 exhibits a Madagascan facies. 



As regards Gonatodes andersonii, any argument derived from its 

 relationship to G. kandiatius ha,s its weak point ; for G. kandianus is, at any 

 rate in some places, a house-lizard', and though it probably originated 

 in the mountains of Ceylon or S. India, it occurs also in the plains ; it 

 may therefore, have been introduced by man into the Andamans. In any 

 case it must be regarded as the ancestor of G. andersonii, which is merely 

 an offshoot from it: whether we look upon the two forms as specifically 

 distinct depends entirely on the answer we are prepared to give to the 

 question, " What is a species ? " I have given the Andaman form 

 a name because it is convenient that things should have names, and 

 because the lizard can be distinguished by characters which appear to be 

 constant; but I should doubt whether it is a ''physiological" species. 

 Poulton (7) in one of the latest general contributions to the sub- 

 ject of specific characters, regards it as impossible, from a scientific 



A It is wortliy of note that the distribution of this species is much wider than 

 that of its allies. 



