ELEVENTH ANNUAL REPORT. 103 



fishes kept in small ponds do not attain the size of those in large 

 ponds since their range and food supply are restricted. 



Feeding. — If large numbers of black bass, rock bass and calico 

 bass are removed for safety to smaller ponds where they may 

 exhaust the natural food supply, it will be necessary to feed them. 

 If they are put in small "nursery ponds" where they are crowded, 

 feeding is imperative. The principal natural food of fishes is iish, 

 which should be perfectly fresh. For young fishes it must be cut 

 and boned, then rubbed through a fine wire screen. Fresh meat 

 or liver must be prepared in the same way. For the details re- 

 specting the feeding of young fishes the reader is referred to 

 the "^Manual of Fish Culture," or some other work on the subject. 



Adult fishes kept in restricted quarters will also require feed- 

 ing. They may be fed largely on live minnows. Among the 

 fish-foods used at the New York Aquarium, are live minnows, 

 live shrimps, chopped fish, beef, liver and clams. 



It is a mistake to suppose that fishes do not require an abun- 

 dance of food. They ma}' Irz'e without it but can not grow. 



JVater Plants. — About one-quarter of the ordinary pond should 

 be as shallow as lo or 12 inches and planted with pondweeds, 

 such as Potamogeton, parrots-feather {MyriopJiylluui), water- 

 celery (Vallis)ieria), hornwort {CeratopJiylliiui) and Cahoiiiba. 

 Suitable plants for the purpose may be found in most streams and 

 ponds, and there are many others than those mentioned. Water 

 plants that are satisfactory in some regions may, however, not 

 be so in others farther north or south. Water-plants are neces- 

 sary as shelter for young fishes, and greatly increase the various 

 forms of small aquatic life necessary for their food. They also 

 serve to aerate the water, which is most important in small and 

 sluggish ponds. They may be planted by tying to stones and 

 dropping them from a boat, or set in the ground after the water 

 has been partially lowered. The slightly greater depths — from 

 one to three feet, may be planted with water-lilies, while the 

 more extensive and deeper portions should be kept clear of 

 vegetation. If the vegetation becomes too thick it can usually 

 be pulled out with a rake, but it is sometimes necessary to cut it 

 with the scythe. Willow and other trees should be planted at 

 some points to furnish shade. 



Aquatic insects, crustaceans and moUusks, bred among pond- 

 weeds, constitute no small feature of the ponds food supply. It 

 is recorded in the "American Fish Culturist," that an electric light 

 over a certain pond was found to attract insects which fell in 

 the water in such numbers as to supply an important quantity of 



