638 THE SPOUTING AND MOVEMENTS OF WHALES. 



orifice of the blowhole during inspiration, a negation more unfortu- 

 nate as the fact is undeniable, and he accompanies this opinion with 

 an argument which can not be admitted. He says, in effect, that this 

 enlargement of the blowhole can not serve to accelerate the inspira- 

 tion in any considerable degree since the nostrils remain always very 

 narrow compared with the quantity of air inspired. Thus, according 

 to Eawitz, the difference between the volume of air which can be 

 taken in by a narrow orifice and that taken in by an orifice ten times 

 as wide is inconsiderable! I leave to him the responsibility for such 

 a conclusion. 



The entrance of the air into the lungs of the large cetaceans as well 

 as the expirations produces a certain sound, which is not a "voice," 

 but simply a sound produced by the strongly inspired air passing- 

 through the relatively narrow orifice. Sometimes, how^ever, the noise 

 is more harj^h, resembling a dull w^histle, and with proper allowance it 

 resembles that produced sometimes in the nasal canals of terrestrial 

 animals which are clogged with mucus or any foreign matter. 



It is unnecessary to say that the cetaceans breathe air alone, and 

 that they are as much inconvenienced as any land animals when the 

 water penetrates into their respiratory organs. 



C. — THE INTERMEDIATE IMMERSIONS. 



When a cetacean has respired, as seen above, it dives, executing a 

 rotating movement indicated by the curvature of the body more or 

 less extended, and thereupon continues to advance under water. There 

 is seen, then, at the surface after respiration, which has been indicated 

 b}^ the presence of the protuberance of the blowhole, the slight con- 

 cavity which marks the rudimentary neck in these animals, then the 

 back always convex for a distance approaching the posterior extremity 

 more or less, according to the species. Thus the right whales show a 

 large part of the back, extending posteriorly beyond the point where 

 the dorsal fin is located in those cetaceans which possess this part. In 

 the humpback the back is also shown to a point behind the dorsal fin. 

 In the finback the dorsal fin is not shown, but the sperm whale shows 

 its dorsal hump and the porpoises their dorsal fins. 



The inmiersion of the animal proceeds from in front backward, 

 always in a curved line, and the cetacean disappears without having 

 shown its tail in any case. 



The period of disappearance is longer or shorter, according to the 

 species, but never exceeds a few minutes. Then the protuberance of 

 the blowhole reappears, the whale respires, shows its back, and disap- 

 pears again. The number of these intermediate immersions before 

 sounding varies according to the species. In general, the whalebone 

 whales execute >)nt few, the toothed whales very many. In all ceta- 

 ceans, however, they are characterized b}' the following: (1) The 



