THE GOLDFISH AND ITS CULTURE. 87 
When of sufficient size, and the proper time has arrived, it 
changes into a pupa, which in turn, becomes the perfect beetle. (See 
illustration.) 
THE BLACK WATER BEETLE. 
(Hydrophyllus piceus. ) 
As the name indicates, this beetle is black, shining with a rich, 
purple lustre. (See illustration.) It is of larger size than the preced- 
ing, and strong in proportion. 
THE BLack WATER BEETLE. 
The beetle itself is a vegetarian, and as such, is not directly 
dangerous to the fish, its larva, however, is voracious without limit, 
destroying all that comes in its way. 
The female of this species spins a white cocoon around the 
posterior portion of its body, with the aid of its hind legs, the cocoon, 
when completed, being the size of a hazel nut. In this it deposits 
its eggs, and after closing it carefully, fastens it to a floating leaf, 
adding to it a little projecting point on the top, which by the 
way resembles a small mast, retires to the water underneath and 
mounts guard. After a few days the young grubs make their 
appearance, at first resembling little whitish worms, but possessing 
six legs near the yellow head. 
It is by the motion of these legs that the grub is propelled through 
the water, continually on the search for something to eat. When at 
