ORDER CETACEA. 481 



form but one and the same orifice, the external diameter 

 of which is about a hundredth of the total length of the 

 individual. 



The spiracles answer the purpose of expelling the water 

 which penetrates into the interior of the Whale's throat, or 

 to introduce into the larynx, and consequently into the 

 lungs, the air that is necessary for the respiration of the 

 animal. They send forth so considerable a volume of 

 water, that it is sufficient instantly to fill a boat. It is also 

 sent forth with amazing rapidity, especially when the 

 Whale is agitated by any violent feeling, and the noise, 

 which is tremendous to those unaccustomed to it, may be 

 heard at a very considerable distance. It is said that those 

 cascades are sometimes carried to a height of thirty or forty 

 feet, and communicate a motion to the surface of the sea, 

 which is quite perceptible at a distance of six thousand 

 feet. 



The organ by which the Whale thus expels the water 

 through his spiracles, consists in two large membranous 

 pouches imbedded under the skin in front of these orifices 

 with which they communicate. Some fleshy fibres very 

 strong, proceeding from the circumference of the cranium, 

 unite above these pouches and compress them violently at 

 the will of the animal. When he wants to rid himself of 

 the superfluous quantity of water in his mouth, he swallows 

 it, but at the same time closes the pharynx and forces the 

 fluid to ascend into the spiracles, where he raises, by the 

 movement he impresses on it, a fleshy valve placed in the 

 spiracle itself towards its superior extremity below the 

 pouches. The water then penetrates into those pouches ; 

 the valve then closes and prevents the water re-entering the 

 mouth, and the animal compressing the pouches with 

 violence, ejects the water to a height proportioned to the 

 force of the compression. 



The Balsenee are truly biped animals, or to speak more 



