82 



ANIMAL LOCOMOTION. 



waved lines, as in walking and flying. — {Vide gg.hli of fig. 

 40, p. 81, and compare with fig. 18, p. 37, and figs. 71 and 7 3, 

 p. 144.) The swimming of man, like the walking, swimming, 

 and flying of animals, is effected by alternately flexing and 

 extending the limbs, as shown more particularly at fie;. 41, 

 A, B, a 



Fig. 41. — A shows the arms and legs folded or flexed and drawn towards the 

 mesial line of the body. —Original. 



B shows the arms and legs opened out or extended and carried away from 

 the mesial line of the body .— Original. 



C shows the arms and legs in an intermediate position, i.e. when they are 

 neither flexed nor extended. The arms and legs require to be in the posi- 

 tion shown at A before they can assume that represented at B, and they 

 3*equire to be in the position shown at B before they can assume that 

 represented at C. When the arms and legs are suc(;essively assuming the 

 positions indicated at A,.B^ and C, they move in ellipses, as explained. — 

 Original. 



By alternately flexing and extending the limbs, the angles 

 made by their several parts with each other are decreased 

 and increased, — an arrangement which diminishes and aug- 

 ments the degree of resistance experienced by the swimming 

 surfaces, which by this means are made to elude and seize 

 the water by turns. This result is further secured by the 

 limbs being made to move more slowly in flexion than in 

 extension, and by the limbs being made to rotate in the 

 direction of their length in such a manner as to diminish the 

 resistance experienced during the former movement, and 

 increase it during the latter. When the arms are extended, 

 the palms of the hands and the inner surfaces of the arms 

 are directed downwards, and assist in buoying up the 

 anterior portion of the body. The hands are screwed 

 slightly round towards the end of extension, the palms acting 



