VI 



CONTENTS 



CHAPTER PAGE 



8. The Sponges — Phylum Porifera 109 



A simple sponge, Scypha — Principle of regeneration — The metazoa — 

 The bath sponge — Classification — Review questions. 



9. Two- Layered Animals — Phylum Coelenterata 118 



Hydra as a typical coelenterate — Other Hydrozoa — The Scyphozoa — 

 The Anthozoa — Classification — Review questions. 



10. The Flatworms — Platyhelminthes 134 



Symmetry of flatworms — Free-living flatworms, the Turbellaria — Organ 

 systems of planaria — Flukes, the Trematoda — Tapeworms, the Cestoda 

 — Classification — Review questions. 



11. Roundworms — The Nemathelminthes 154 



The large roundworm of man. Ascaris — Organ systems of ascaris — The 

 hookworm — The trichina worm — The pinworm — Elephantiasis — The 

 hair worm — Some principles of parasitology — Classification — Review 

 questions. 



12. Segmented Worms — The Annelids 169 



Life processes of the earthworm — A marine annelid, the clam worm — 

 Parasitic annelids, the leeches— Classification — Review questions. 



13. Animals With Jointed Legs — The Arthropods 181 



Importance of the arthropods— Characteristics of the phylum— Class 

 Crustacea — The crayfish as a typical crustacean — Homology and anal- 

 ogy — Other crustaceans — Classification — Review questions. 



14. Arachnids, Centipedes, and Millipedes — Arthropods 



(cont.) 198 



Spiders— Economic importance of spiders— Scorpions— The granddaddy 

 longlegs— Mites— Ticks— King crab— Centipedes— Millipedes— Classifi- 

 cation — Review questions. 



15. The Insects — Arthropods (cont.) 210 



Economic importance of insects — Insect characteristics — Insect meta- 

 morphosis—Insect wings— Insect food and feeding habits— Insect pro- 

 tection — Insect voices — Insect reproduction — Review questions. 



16. A Social Insect — The Honeybee 227 



Bee castes — Duties of house bees — Duties of field bees — The dance of 

 the bees — Nectar and pollen collection — Swarming — Nuptial flight — 

 Control of sex of offspring— Beekeeping— Wintering— Bee learning- 

 Review questions. 



17. Insect Orders 240 



Thysanura— Collembola— Ephemerida— Odonata— Plecoptera-nOrthop- 

 tera — Isoptera — Dermaptera — Coleoptera — Mallophaga — Anoplura — 

 Hemiptera — Homoptera— Neuroptera— Lepidoptera— Diptera— Sipho- 

 naptera— Hymenoptera— Classification — Review questions. 



