CARE OF CAPTIVE ANIMALS — WALKER 363 



total darkness. Feed sparingly on enchytrae, ground shrimp, daphnia, waxworms, 

 cr bits of raw meat. Necturus, the two North American colored forms, inhabit 

 warm, sluggish streams. Feed fish eggs, enchytrae, mealworms, small bits of fish, 

 and acquatic insects. 



SIREN ( Sirenidae) . Feed small fish, fish eggs, tadpoles, aquatic insects or their 

 larvae, enchytrae, earthworms. Aquatic, so should have pool of water. 



FISH 



Fish kept in captivity for exhibition purjwses may be roughly divided into two 

 classes, as follows: 



Small, mainly tropical fish, often beautiful, brilliantly colored creatures, can be 

 kept in small aquaria without inconvenience, and sometimes add real beauty to 

 the home. Great interest has been taken in so-called tropical fish raising, and 

 Some excellent publications have been issued on the subject. (See bibliography.) 



Larger fish require large tanks with special provisions for aeration, filtering, 

 cooling or warming the water, and to keep them involves numerous problems 

 which only a large aquarium could undertake. It is therefore not advisable to 

 attempt to treat the keeping of fish in this work. 



Such large aquaria as the John G. Shedd Aquarium, Chicago, the Aquarium of 

 the New York Zoological Society, New York City, the Steinhardt Aquarium, San 

 Francisco, the Regents Park Aquarium operated by the Zoological Society of 

 London, and numerous others have issued publications relative to the raising of 

 fish. The United States Bureau of Fisheries, now a part of the United States 

 Fish and Wildlife Service, Department of the Interior, has issued many publica- 

 tions relating principally to commercial fish. In addition, many facts are con- 

 tained in articles and reports issued through various biological laboratories. 



INVERTEBRATES 



There are a vast number of invertebrates, including protozoa, worms, soft- 

 bodied marine forms, crabs and crayfish, insects and mollusks that are attractive 

 to many people. Many of these make interesting and sometimes beautiful exhibits, 

 but a discussion of their care is beyond the scope of this paper. Information 

 regarding the keeping of such creatures can be obtained from entomologists or 

 other biologists. The raising and study of such forms can be a fascinating work 

 or hobby for persons who are interested. 



LITERATURE RELATING TO THE CARE OF ANIMALS 



A vast amount of material on the subject of animals and their 

 care has been written. It is not possible to give here even a reason- 

 ably complete list of such literature. Governmental agencies of 

 practically all countries throughout the world have issued publica- 

 tions on domestic and wild animals. In our own country, the United 

 States Fish and Wildlife Service, of the Department of the Interior, 

 has many bulletins and leaflets on North American birds, mammals, 

 reptiles, amphibians, and fish, some of which treat of the raising of 

 fur-bearing animals, certain birds, fish, and invertebrates. Scientific 

 societies and various research agencies have put out many excellent 

 works. Natural histories and similar works — dealing specifically 



