98 ANIMAL RESOUKCES OF THE UNITED STATES. 



2. PRESERVATION" OF GAME, FISH, &c— Continued. 



b. Fish-ways: 



Steps contrived by arrangement of rocks and bowlders. 

 Inclined plane without steps : 



Plain, (Pennsylvania.) 

 With partitions at right angles : 



" Rectangular compartment." 



Brackett's. 

 With oblique partitions : 



Foster's. 



Swazey's. 



*** From natural enemies. 



c. Apparatus for destroying injurious species : 

 Oyster-bed tangles, (see under B, 12.) 



3. CARE OF ANIMALS IN CAPTIVITY. 



a. Tethers and hopples. 



b. Cnges and pens : 



Kennels for dogs, &c. 

 Cages for animals. 

 Cages for birds. 

 Cages for insects. 

 (West India fire-fly trap.) 



c. Fish-cars and other floating-cages for aquatic animals. 



d. Aquaria : 



Globes. 

 Aquaria. 



e. Hives and other cages for insects. 



/. Live-boxes, troughs, &c, for microscopists' use. 

 g. Fish-ponds, fish-farms, (models.) 



4. ENEMIES OF USEFUL ANIMALS. 



a. Intestinal worms and other internal parasites. 



b. Fish-lice, barnacles, and other external parasites. 



c. Predatory animals not elsewhere exhibited. 



III. PROPAGATION. 



5. PROPAGATION OF MAMMALS. 



a. Methods of mink culture. 



b. Methods of culture of domesticated animals. 



