COLOR IN ANIMALS 



143 



different genera (Plate 79). Many of our common Ameri- 

 can snakes imitate poisonous serpents in one peculiar habit, 

 though not in exact color. Poisonous serpents when cor- 

 nered and irritated have the habit of flattening their heads 



FlG. 42. Moth from India (Attaciis atlas), at the tips of whose wings are markings resembling 



those upon the head of a cobra. 



so that they become even more triangular than when at rest, 

 and they show a pugnacity that is very forbidding. Most 

 of our little harmless snakes, when cornered, will behave in 

 much the same manner, flattening the head and making it 

 triangular, and by their hissing and striking they seem to 

 suggest that they are dangerous. 



