142 ELEMENTARY ZOOLOGY. 



Many butterflies when resting resemble leaves. The 

 body and wings of the katydid are green and the wings 

 are veined somewhat like a leaf (Fig. 90). The larvae 

 of some of the moths, often called " measuring- worms, " 

 are remarkably like the twigs on which they crawl. 

 When disturbed they often hold on by the posterior legs, 



FIG. 31. A sea-horse, Phyllopteryx eques. From Eckstein. 



Questions on the Figure. Compare this figure of a sea-horse with 

 figures of other species, and note the chief differences between them 

 and the typical fishes. At what point does the tail of the fish end? 

 What about the figure suggests protective resemblance ? 



and extend the body out in such a way as to make an 

 angle with the twig, remaining in this position for many 

 minutes. Similarly, devices for concealment are found 

 among the fishes (see Fig. 31). 



Other devices whereby animals protect themselves 

 from their enemies are seen in the electric organs of some 

 eels and other fish, in the poisonous fluids with or with- 

 out special stinging organs as in ccelenterates, bees, 

 spiders, a few fishes, and some snakes ; also in the repulsive 

 odors of the skunk, the civet, and many caterpillars. 



