478 BIOLOGY FOR BEGINNERS 



letins Nos. 142, 234, 252, 283, 333 and others. Rural School Leaflets, list 

 on application. 



U. S. Department of Agriculture Bulletins, Farmers' Bulletins Nos. 165 

 264, 275, 564, etc., Bulletin No. 492, etc., Circulars Nos. 36, 98, etc. 



The above Government publications are merely a suggestion; lists can 

 be had for the asking, and hundreds of useful pamphlets can be obtained, 

 especially in regard to insects. 



(See also Chapter 25 on "Insects and Disease.") 



SUMMARY 

 General uses of animals. 



1. Food. 6. Feathers. 



2. Transportation. . 7. Ivory, horn, glue, hair, gelatine. 



3. Fabric fibers. 8. Pollenation, seed dispersal. 



4. Fur. 9. Scavengers. 



5. Leather. 10. Destroying harmful forms. 



Harmful kinds of animals. 



1. Protozoa (diseases). 



2. Insects (destroy crops). (Transmit disease.) 



3. Wild animals (destroy man and domestic animals). 



Economic value of animals. 

 Protozoa. 



1. Food for higher animals, clams, Crustacea, fish, etc. 



2. Deposit shell as chalk beds. 



3. Act as scavengers in water. 

 Sponges. 



1. Skeleton of horny forms used as "bath sponge." 



2. Preparation: collected, rotted, washed, dried, bleached. 

 Coelenterates. 



1. Corals, reef, and continent builders. 



2. Coral deposits, now limestone beds. 



3. Precious coral. 

 Echinoderms. 



1. Starfish harmful to oysters. 



2. Sea-cucumbers eaten by Chinese, etc. 

 Worms. 



1. Earthworms necessary in cultivated soil. 



2. Parasitic worms cause disease in man and animals. 

 Molluscs. 



1. Raw food, also cooked, clams, oysters, etc. 



2. Shells furnish mother-of-pearl, buttons, chicken feed. 



3. Precious pearls (Persia and Ceylon). 



4. Shells for money and ornament. 



5. Squids for bait and cuttle bone, sepia. 



