THE GOLDFISH AND ITS CULTURE. 85 



the four nearest the head are short, but the third pair are very 

 long, different in shape from the others, very much resembling 

 boat oars. When in the water, the insect swims upon its 

 back, using the hind legs as oars for propulsion, while the front ones 

 are instrumental in seizing its prey. Young fish, tad-poles, and 

 other insects, all contribute to supply it with food, to the former, 

 especially, it is a very dangerous enemy. The instrument or weapon 

 with which the insect makes the attack upon the victim is a strong, 

 conical beak. 



It is believed that when making the attack, the boat-fly injects 

 poison into the wound it makes, as seems to be proven by the fact 



THE BOAT FLY. LARVA OF DRAGON FLY. 



that when once attacked, though subsequently escaping, the victim 

 always dies in a short time. When upon larid, this fly crawls along, 

 in an upright position, dragging its oars behind it. In the evening, 

 and at night, it likes to leave the water and make excursions to 

 other ponds or creeks ; from this habit the culturist may take 

 warning. Its eggs are deposited against the stems of aquatic plants 

 in the early spring, and again in mid-summer, so that one season 

 produces two crops of them. 



The young make their appearance soon after, immediately 

 following .the example of the parents by swimming upon the back 

 and eating almost anything they happen to meet. The accompany- 



