CETACEANS. 151 



whales, a necessity for casting water from their spiracles 

 should rather exist in the profound depths, where they 

 feed, than on the surface, where their business is chiefly 

 to respire. 



In support of the opinion that water is ejected from 

 the spiracles, it may be suggested, that although in 

 size, capacity of lungs, and in habits, herbivorous 

 cetacea, and some seals, accord with many spouting- 

 whales, they do not, nevertheless, exhibit the pheno- 

 menon of visible respiration ; (if spouting be such ;> and 

 also, that the complex arrangement of muscles, valves, 

 cavities, and tubes, in the spiracular canals of spouting- 

 whales, would imply that their function exceeds that of 

 simply receiving and emitting air. Although from this 

 we may reserve, how far such complex organization 

 may be essential to expand the spiracles for the re- 

 ception of air, or to obstruct and eject any quantity of 

 water which may be accidentally received into the 

 nostrils during the act of inspiration. 



The entire question is involved in much perplexity ; 

 but it is probable, that the spouting-canal may perform 

 both the offices attributed to it, at distinct times, and 

 in a distinct manner a conclusion to which I have 

 been led by observing the common Dolphin (Delphinus 

 delphis). It is very usual to hear these small whales 

 blow with a short puffing sound, without any attendant 

 spout being perceptible ; whilst, at other times, I have 

 seen them cast distinct but irregular jets of water from 

 their spiracle. One of this species, moreover, which 

 was harpooned from the bows of the Tuscan, and taken 

 on board alive, expanded its spout-hole, and produced 

 a sucking sound on inspiration, and emitted a low 

 explosive sound on expiration; but no exhalation of 

 vapour was visible. 



