x ANIMAL LIFE 



CHAPTER IV 



MOVEMENT 



A. The spectacle of movement 26 



1. Increasing finish of movement is accompanied by 

 elevation in the scale of being Insects Fish . . 26 



2. The finish and unweariedness of movement . . 27 



3. Its highest manifestation The migration of animals 28 



B. The modes of animal motion The analogy of a boat 

 Leverage in swimming, walking, and flight Other forms of 

 locomotion 29 



C. The movements of animalcules Ciliary movement The 

 value of cilia Movement essentially innate . . . 33 



I), i. The movement of worms and Crustacea .... 37 

 2. Swimming, walking, and flight of insects .... 39 

 E. The locomotion of vertebrates : 



i. Fish Their methods of swimming The use of the 

 tail and fins Free swimming and ground fish Attempts 



at walking and flight 43 



j. Movement on land Support and propulsion 

 Movement and rest in an erect position The changes 

 which have converted aquatic locomotor organs into ter- 

 restrial ones 48 



3. Amphibia and Reptiles Mammals Running, climb- 

 ing and aquatic mammals Whales and seals Flying 

 mammals Bats 50 



4. Birds Their flight Adaptation of the body- 

 Wings Feathers Methods of gliding and active flight 

 Their adaptation for perching, running, and swimming 



The structure of the legs and feet 57 



CHAPTER V 



THE QUEST FOR FOOD 



A. The source of animal food : the quest for plants : 



1. The need for food Dependence of animal on plant 

 Me The feeding of fixed animals The value of higher 

 plants to animals Windfalls Leaf mould. ... 65 



2. The feeding of Crustacea and insects Their jaws, 



lips, and tongues The services of insects to plants . . 68 



