15° 



Handbook of Nature-Study 



such dull-colored goldfish in the Delaware and Potomac and other east- 

 ern rivers. It is almost inconceivable that one of the brilliant colored 

 fishes, if it chanced to escape into our ponds, should escape the fate of 

 being eaten by some larger fish attracted by such glittering bait. 



The goldfish, as we see it in the aquarium, is brilliant orange above and 

 pale lemon-yellow below; there are many specimens that are adorned 

 with black patches. And as if this fish were bound to imitate the precious 

 metals, there are individuals which are silver instead of gold: they are 

 oxydized silver above and polished silver below. The goldfish are closely 

 related to the carp and can live in waters that are stale. However, the 

 water in the aquarium should be changed at least twice a week to keep it 

 clear. Goldfish should not be fed too lavishly. An inch square of one of 

 the sheets of prepared fish food, we have found a fair daily ration for five 

 medium sized fish ; these fish are more likely to die from overfeeding than 

 from starving. Goldfish are naturally long-lived; Miss Ada Georgia has 

 kept them until seven years old in a school aquarium; and there is on 

 record one goldfish that lived nine years. 



Too often the wonderful common things are never noticed because of 

 their commonness; and there is no better instance of this than the form 

 and movements of a fish. It is an animal in many ways similar to ani- 

 mals that live on land; but its form and structure are such that it is 

 perfectly adapted to live in water all its life; there are none of the true 

 fishes which five portions of their lives on land as do the frogs. The first 

 peculiarity of the fish is its shape. Looked at from above, the broader 

 part of the body is near the front end which is rounded or pointed so as to 

 cut the water readily. The long, narrow, hind portion of the body with 

 the tail acts as a propeller. Seen from the side, the body is a smooth, 

 graceful oval and this form is especially adapted to move through the 

 water swiftly, as can be demonstrated to the pupil by cutting a model of 

 the fish from wood and trying to move it through the water sidewise. 



Normally, the fish has seven fins, one along the back called the dorsal, 

 one at the end of the tail called the tail or caudal fin, one beneath the rear 

 end of the body called the anal, a pair on the lower side of the body called 

 the ventrals, and a pair just back of the gill openings called the pectorals. 

 All these fins play their own parts in the movements of the fish. The dor- 



'Gili opening 

 Vfcntrol fin 



Goldfish with the parts named. 

 This figure should be copied on the blackboard for reference. 



