ANALYSIS OF CONTENTS 



Chap. I. Introduction. Problems which arise about 

 animal locomotion. Diiferent number of limbs and 

 different modes of bending them found in different animals. 



II. Assumption of generally-accepted principles and 

 definitions. 



III. Animal movement requires (1) a resisting surface 

 against which the limbs can press, (2) a distinction of 

 active and passive parts in the animal. 



IV. The dimensions of living bodies. Superior and 

 inferior determined by function and not by position. 

 Plants and animals compared. Distinction of front and 

 back, right and left. The right, as the source of move- 

 ment, superior to the left. Man the most highly differen- 

 tiated of the animals. 



V. Bipeds, quadrupeds, polypods and footless animals 

 distinguished. Quadrupeds inferior to bipeds. Man the 

 highest form of biped, being the most " natural." 



VI. All movement in the animal must originate in a 

 common centre, equidistant from the centres of movement 

 in the limbs. 



VII. Red-blooded animals move at four points : such 

 animals are a continuous whole, while bloodless animals 

 and polypods are composed of a number of separate 

 entities. Even limbless red-blooded animals move at 

 four points. 



VIII. Reason for the absence of limbs in snakes. Limbs 

 necessarily even in number. 



IX. Flexion necessary to movement, even in limbless 

 animals. Its mechanism explained. Illustrations from 

 leaping, flying, and swimming animals. 



X. Movement of birds. Use of the tail to guide flight. 

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