CETACEA. 



575 



We have now to speak of a phenomenon which has given 

 rise to a considerable amount of controversy namely, what is 

 known as the " blowing" or " spouting" of the whale. In all 

 the Cetaceans the nose opens by a single or double aperture 

 (the latter in the Balanida*} upon the top of the head, and 

 these external apertures or nostrils are known as the " blow- 

 holes " or " spiracles." The act known to the whalers as 

 " blowing " consists in the expulsion from the blow-holes of a 

 jet of what is apparently water, or at any rate looks like it. The 

 act is performed by the whale upon rising to the surface, and 

 it is usually by this that the whereabouts of the animal is dis- 



Fig. 245. Diagram of the Baleen-plates of a Whale, a a Section of the palatal sur- 

 face of the upper jaw, showing the strong median ridge or keel ; b b Baleen-plates 

 sunk at their bases in the palate ; ff Fibrous margin of Baleen-plates. 



covered. The old view as to what takes place in the act of 

 blowing is, that the whale is really occupied in getting rid of 

 the surplus water which it has taken in at the mouth and 

 strained through the baleen-plates. The modern and doubt- 

 less correct view, however, is, that the water which has been 

 strained through the baleen really makes its escape at the side 

 of the mouth, and does not enter the pharynx to be expelled 

 through the nose. Upon this view the apparent column of 

 water emitted from the blow-holes in the act of blowing con- 

 sists really of the expired air from the lungs, the contained 



