PROGRESSION ON AND IN THE WATER. 



89 



of his arms and legs, and the awkward manner in which they 

 arc apphed to and withdrawn from the water. 



Swimming of the Turtle, Triton, Crocodile, etc. — The swim- 

 ming of the turtle differs in some respects from all the otlier 

 forms of swimming. While the anterior extremities of this 



yiG. 44.— The Turtle {Chelonia imbricaia)^ adapted for swimming? and diving, 

 the extremities being- relatively larger than in the seal, sea-bear, and wal- 

 rus. The anterior extremities have a thick anterior margin and a thin 

 posterior one, and in this respect resemble wings. Compare with figs. 36 

 and 37, pp. T4 and 76. — Original. 



quaint animal move alternately, and tilt or partially rotate 

 during their action, as in the sea-bear and walrus, the posterior 



Fig. 45. — The Crested Newt (Triton cristatv.s, Laur.) In the newt a tail is 

 superadded to the extremities, the tail and the extremities both acting in 

 swimming. —Ori'jinal. 



extremities likewise move by turns. As, moreover, the right 

 anterior and left posterior extremities move together, and re- 

 ciprocate with the left anterior and right posterior ones, the 

 creature has the appearance of walking in the water (fig. 44). 



