WAKNING COLORATION. 



181 



position that the reptile was for some reason or other to be 

 avoided by its foes. Now, Helodenna is the only certainly 

 known case of a poisonous lizard : it has grooved teeth, which 

 ■conduct the poison from the glands which secrete it, con- 

 structed on a plan similar to that of many poisonous serpents ; 

 and it has been proved, by actual experiment upon some 

 specimens exhibited in the Zoological Society's Gardens, that 

 the bite of this creature is fatal to many small animals. 



Fig. 20.— Coral Snake. 



It is sluggish in its habits uutil thoroughly roused and 

 infuriated. For a creature of this kind some advertisement 

 of its deadly qualities is most useful. The poisonous snakes 

 are, perhaps, not as a rule brilliantly coloured, but there are 

 ])lenty of exceptions to this rule : the deadly Elaps of Central 

 and South America (fig. 20) is ringed with black and red, 

 and thus furnishes another example of the common plan of 

 coloratiou and the often similar colours which are utilised for 

 warning purposes. This lias been emphasised by Mr. Poulton, 



