636 THE SPOUTING AND MOVEJtfENTS OF WHALES. 



ture, and it is certain that the phenomenon of the expiration of ceta- 

 ceans can be compared from every point of view with the phenomena 

 presented by gases under constraint. There is, in effect, a vast pul- 

 monary reservoir inclosed in a powerful thoracic cage, comnuinicating 

 w^ith the exterior by an orifice much reduced in comparison with the 

 capacit}" of the lungs, and this orifice is opened suddenly at the 

 moment of expiration. The proof that the air is expelled under strong 

 pressure is that the spout rises to a very great height and especially 

 that its emission produces a harsh sound, so characteristic that all 

 authors have compared it to the escape of steam under pressure. 



This idea of Portier's seems to me to explain admirabl}^ all the 

 peculiarities of the spout; thus, the spout of the small whales is not 

 seen because their muscular power is feeble and the air escapes under 

 a mininuun pressure. The expiration which follows the first appear- 

 ance of the Avhale after sounding is more forceful than the others, 

 because the animal at the moment of diving has expanded its lungs 

 more strongly than for ordinary immersions and consequently the air 

 is under a more considerable pressure. 



I do not wish to maintain that the refrigeration consequent upon 

 the phenomenon of restraint is the sole reason of the visibility of 

 the spout. It is necessary to make a distinction. In the Tropics it is 

 certain that the condensation of the vapor is due solely to refrigera- 

 tion caused by restraint, but in the polar regions the phenomenon of 

 the buee complicates the causes of this appearance. 



6. Odor of the sjjout. — As I have already remarked in another 

 place (p. 632), the odor of the spout of the humpback is nauseating, 

 and confirmation of this observation will be found in Baer (1864), 

 Lilljeborg (1866), Jouan (1882), and other authors whom it is unneces- 

 sary to cite here. Jouan (1882, p. 12) remarks, indeed, that this is 

 observed especially among the large species of cetaceans, and that the 

 spout of the sperm whale is particularly fetid, as it provokes nausea 

 and " produces the effect of a blister on the skin." I leave to this 

 author the entire responsibility of this last assertion, and would recall 

 simply that the fetidness of the spout is habitual in the large whales 

 and is not peculiar to the humpbacks. 



I have attributed this bad odor somewhat rashly to the bodies of 

 the animals which have decomposed in the whalebone of the baleen 

 whales, a fact often observed. Fishes found in the mouth of Balae- 

 noptera 2?hysalus (common finback) in process of decomposition have 

 been cited, but in addition to the fact that this hypothesis can not be 

 applied to the sperm whale, which is without whalebone, it is also 

 incompatible with the arrangement of the respiratory canal, which is 

 completely isolated from the cavity of the mouth. It is necessar}', 

 therefore, to look for the source of infection in the respiratory appa- 

 ratus itself. 



