116 
THE FRESH-WATER AQUARIUM. 
these, for they will breed in the tank; and as the stickleback builds his 
nest somewhat like a hanging-bird's—a regular little house, with back 
door and front door—and is a lively, spirited fellow, he will afford you a 
deal of amusement. A small eel or two -will be nice enough until they 
grow large. The gudgeon, and the catfish, dace, or rockfish, will answer. 
So will the sunfish, while very small. As he grows older he is apt to dis¬ 
turb the others. A small goldfish, where you can obtain it, will add variety, 
and the newt, or water-lizard, to be had in every pond and stream, must 
not be forgotten. They soon grow tame, and will feed from your finger. 
The fish must be fed occasionally with small pieces of worms and shreds 
of lean beef, cut fine. Occasionally a few dough-pills is a kind of medicine 
they will take with relish. Do not starve them, but, on the other hand, do 
not overfeed them. Whatever they do not eat must be removed, as its 
decomposition will affect the water. 
Theoretically, the balance of animal and vegetable life will supply the 
fish with enough oxygen; but practically not, because you cannot attain the 
exact proportion between the two. The water must be aerated from time 
to time, and this is done with a small pair of common bellows, with which 
you blow air into the water, to the comfort and satisfaction of the inhabit¬ 
ants of your pond. 
