INTRODUCTION. 
19 
natural means of obtaining food, the animals become emaciated, and at last expire. 
The same may be said of the Delphinidce or Dolphins. 
All the Cetaceans propel themselves through the water by the action of their 
pectorals and caudal fin, and the individual motions of the various species are simi- 
lar. Usually a small portion of the animal is seen rippling along as it makes its 
respiration, then, after a few moments, settling below the surface, it again appears 
in the same manner. When descending to the depths below, it rises a little, as in 
figure 1; then pitching headlong, "rounds out," as in figure 2; then "turning 
8 
flukes," as in figure 3, disappears. Thus these animals wander through the track- 
less waters in their migrations ; or, when roving about at leisure on their feeding or 
breeding grounds, they are sometimes seen in various attitudes, which will be 
mentioned hereafter. 
