110 REPTILES OF THE WORLD 



already annoyed by varied hordes of insects forms, the 

 apparition of these heavy but stealthy forms darting 

 across the ceiling over his head, is weird and startling. 

 An attempt at capture intensifies the impression, for 

 the strange thing darts over the walls with the ease of 

 a gigantic fly. Suddenly it may scurry for the window 

 and away, but if the light continues to burn, others of 

 its kind soon appear. Thus is life in the tropics asso- 

 ciated with visits of the geckos that enter the houses in 

 search of insect prey. 



Among lizards the present creatures are about the 

 only forms that produce sounds beyond sharp, angry 

 hissing. A number of the geckos gives voice to a 

 distinct clicking sound which might roughly appeal to 

 such words as yecko or gecko — sounds produced by 

 clicking the tongue against the roof of the mouth — 

 hence the origin of the popular name. In places where 

 the geckos are very numerous these sounds may be as 

 continuous as the calls of nocturnal insects. The voice 

 of a gecko appears to be produced by a convulsive move- 

 ment of the tongue. A few species are alleged to pro- 

 duce sharp sounds by rubbing certain plated portions 

 of the body — in the same fashion as all insects produce 

 their calls. 



Geckos are oviparous, depositing white, bluntly oval 

 or round, hard-shelled eggs. The males are generally 

 larger and proportionately stouter than the other sex. 

 Decided changes of color are to be observed among 

 the majority of the species. 



Curiously enough, these absolutely innocuous animals 

 are often regarded as extremely venomous; they are 

 not only thought to be capable of dealing an envenomed 

 bite, but actually poison every object over which they 

 run. And most peculiar is the fact that this belief is 



