THE GREAT WATER BEETLE. 85 



that of walking, which is by no means so conducive 

 to rapid progression. Hence the comparatively small 

 Dyticus is said often to find an easy prey in his un- 

 wieldy brother. The Hydrophilus is, however, alto- 

 gether of a rather peaceful disposition; his food 

 consists principally of vegetable matters, although he 

 is not so strict a vegetarian as to deny himself a meal 

 of animal food when he meets with a dead mollusk or 

 larva in the course of his peregrinations. Like the 

 Dyticus he is well provided with wings, and makes 

 use of them freely in nocturnal rambles. 



Whatever objection the perfect Hydrophilus may 

 have to an animal diet, his larva certainly has no 

 vegetarian scruples, but feeds voraciously upon small 

 mollusca, and other aquatic animals. In its form it 

 is not unlike the larva of Dyticus, but is much fatter, 

 and altogether destitute of the hungry rapacious 

 aspect of that little tyrant of the fresh waters. Its 

 head is of a singular form, being flattened above, and 

 very convex beneath; it is armed with a pair of 

 strong mandibles, and the larva captures its prey by 

 suddenly throwing back its head. According to 

 Lyonnet, it is so ingenious as to convert its back into 

 a sort of table for the more convenient consumption 

 of its food. The larva also exhibits a good deal of 

 cunning when exposed to any danger ; he has the art 

 of rendering his body soft and flaccid like an old cast 

 skin, and if this ruse threatens to be unsuccessful, he 

 immediately discharges a disagreeable blackish fluid, 

 which, according to some writers, serves the same 

 purpose as the ink of the Cuttle-fish, forming a cloud 

 in the water to cover his escape. 



In the course of its growth, this larva moults three 

 times, and when mature, measures about three inches 



