628 THE SPOUTING AND MOVEMENTS OF WHALES. 



and expirations. This respiratory rhythm, which land mammals utilize 

 only accidentally, forms the normal rhythm of the respiration of the 

 whales, and, I may add, of all terrestrial vertebrates which are modi- 

 tied for an exclusively aquatic life (for example, the leatherback turtle, 

 the water snakes, etc.). 



The whale, having' returned to the surface after a long inuuersion, 

 emits then a prolonged expiration, makes a short inspiration, dives a 

 little, reappears to breathe, dives again, and thus many times in suc- 

 cession; then he makes a long inspiration and plunges into the depths 

 for a considerable time. I will now analyze successively all these 

 movements. 



A. — EXPIRATION, OR " SPOUT." 



This is the only part of the act of breathing which has attracted the 

 attention of the whalers, and they have given to it the special name of 

 "souffle" in French, or "blow" or "spout" in English. 



1. The moment at ivldcTi the '"'' spout^'' is j^^oduced. — Expiration is 

 produced exactl}^ at the moment when the summit of the head, on 

 which the blowhole is placed, arrives at the surface. Therefore, in 

 general, it is the protuberance of the blowhole which indicates the 

 presence of the animal. It is, moreover, at this moment the most 

 prominent part of the body, because whales have the faculty of pro- 

 truding this part of the blowhole. (I have proved this for the whale- 

 bone whales, and it is probably true of the toothed whales.) The 

 movement of the protuberance of the blowhole is very rapid, and 

 Buchet (1895) is the only one who has pointed this out. Whalers told 

 him, indeed, that when a whale blows "the blowhole forms a very 

 large protuberance," which disappears when the animal is dead. 



In BalEenoptera muscidus L. (the sulphurbottom) the median region 

 of the back often appears before the protuberance of the blowhole. 

 In the sperm whale that which appears first is the dorsal [hump?], 

 according to the opinion of Beale (1839), who appears to have care- 

 fully observed these animals. As to the porpoises and the ziphioid 

 whales, it is possible that their blowhole is not extensible, but it is also 

 the top of the head which appears first above water. 



.^. Duration of the spout. — The duration of the spout is variable and 

 depends on the size of the whale. The large whales spout longer than 

 the small ones, and the first spout after sounding is much longer than 

 the intermediate spoutings. I have estimated it at five or six seconds 

 for Bald&noptera muscidus L. (the sulphurbottom) and at three or four 

 seconds for the humpbacks. Beale (1839) mentions six seconds for the 

 sperm whale. As to the porpoises, the duration of their spout does 

 not exceed two seconds. Whatever the length may be, the spout 

 always lasts longer than the inspiration. I will return to this subject 

 in connection with the second part of the respiratory act. 



