62 COMPARATIVE ANATOMY 



of life, they rarely produce visible spoutings, but 

 carry on respiration in a manner more nearly re- 

 sembling animals, not inhabitants of the water. 



After " their spoutings are out," to avail ourselves 

 of the expressive phraseology of the whalers, most 

 of the Cete, as we have already stated, descend 

 into the depths of the ocean, where they are some- 

 times exposed to the pressure of one hundred and 

 fifty-four atmospheres, equal to about a ton upon 

 each square inch. We have seen how this pressure 

 is met, by a peculiarity of the integuments ove- 

 the whole surface of the body ; it now remains 

 to state how the delicate apparatus we have just 

 described is defended from danger from the same 

 cause. The external opening of the blow-holes is 

 in some of the larger species an opening or slit of a 

 foot in length, the tube itself is of large dimensions, 

 and the chest is a great chamber of air : by what 

 means then is water prevented, under this immense 

 pressure, from entering the lungs and so destroying 

 the animals ? We answer : It is mainly by a set of 

 valves which act upon the same principle in all the 

 genera, but which are varied in each, by a number 

 of contrivances equally extraordinary, beautiful, and 

 efficient. We shall illustrate this remark by epito- 

 mizing a short portion of Pallas' excellent ac- 

 count of the apparatus in the Beluga or white 

 whale. The blow-hole opens in the most elevated 

 part of the head, and this opening is circumscribed 

 by a double arch. The skin is drawn towards this 

 orifice, and forms over it in front a soft papillary 



