THE ARCTIC SEAS. 137 



Whale, the force with which the water ruslics into 

 tlie mouth would inevitably carry a large portion of 

 the fluid down upon the lungs, and the animal woidd 

 be suffocated. The windpipe is therefore carried 

 upward in a conical form, with the aperture upon 

 the top, and this projecting cone is received into the 

 lower end of the blowing-tube, which tightly grasps 

 it ; and thus the communication between the lungs 

 and the air is effected by a continuous tube which 

 crosses the orifice of the gullet, leaving a space on 

 each side for the passage of the food. 



It is doubtless to give increased power of resist- 

 ance to the eye of the "VVliale in the pressure of 

 enormous depths, that there is a peculiar thickness 

 in the sclerotic coat. This is the part which in man 

 is usually called the white of the eye. " When we 

 make a section of the whole eye, cutting through the 

 cornea, the sclerotic coat, which is as dense as tanned 

 1 leather, increases in thickness towards the back part, 

 and is full five times the thickness behind tliat it is 

 at the anterior part. The fore part of the eye sus- 

 tains the pressure from without, and requires no ad- 

 ditional support ; but were the back part to yield, the 

 globe would then be distended in that direction, and 

 the whole interior of the eye consequently suffer de- 

 rangement. We see, then, the necessity of the coats 

 being thus remarkably thickened behind." * 



Another no less interesting deviation from ordinary 

 structure is found in the skin ; the object still being 

 defence against external pressure. Everyone is pro- 

 bably aware that the body of the Whale is encas-^d in 



• Paley's ^'at. Theol., Bell and Brougham's edit. p. 40. 



