ANIMALS FOR. 



will find in the whole structure of these creatures 

 marvellous adaptations to their position, in creation. 

 The Dyticus is much more ravenous than the 

 Hydrophilus, and everything eatable will suffer 

 more or less from its attacks. Even the stickleback 

 is no match for it, and tadpoles it devours by dozens 

 in the day. It has no hesitation in attacking the 

 Hydrophilus, though nearly twice its size. Its 

 larvse are as destructive and tyrannical as itself, 

 and have got the unenviable title of "Water-Devils." 

 I once put two into a bottle together, and carried 

 them for about an hour in my pocket ; on looking 

 at them at the end of that time, I found, in spite 

 of being in the dark 

 and agitated in my 

 pocket, that Cain had 

 slain and eaten his 

 brother Abel. They 

 attack almost every- 

 thing indiscriminate- 

 ly ; the Water-Scor- 

 pions (Nepa) are often 

 their victims (Fig. 1 3). 

 Most of the water- 

 beetles fly at night, 

 and if the Aquaviva- 

 rium is not covered 

 over, they may thus 

 be lost. FIG. 13. 



The genus Colym- 



betes is another member of the family Dyticidce, 

 and embraces species of water-beetles of a smaller 

 size though not less interesting in their habits 

 (Figs. 14 and 15). 



The little family of Whirlgigs, also Beetles 

 (@yrinidce), should not be neglected. They may be 

 easily known by their whirling movements on the 



