86 



SUBKIXGDOM VERTEBKATA. 



Fig. 138. 



Balcena rnystic'etus, Right Whale. 



The veins being destitute of valves, this huge animal 

 bleeds to death from the single thrust of a lance, and in its 

 last struggles, if the lungs are pierced, blood is forced out 

 with the breath. 



The whale has a reserve system of blood-vessels. As fast 

 as the venous blood returns and flows into a waste reservoir, 

 a portion of the extra arterial blood passes into the circula- 

 tion, and thus it can 

 remain under water 

 for an hour. Being 

 an air-breathing ani- 

 mal, it must come 

 quickly to the sur- 

 face; hence its tail* 

 is flattened horizon- 

 tally instead of verti- 

 cally, that a rapid 

 stroke may throw up 

 the head. Its skin 

 consists of interlaced fibres, among which the fat is diffused 

 to the depth, in some instances, of two feet,f forming the 

 "blubber." A wise Creator adapted this thick, non- 

 conducting, India-rubber-like coating to withstand the 

 tremendous pressure of the water J and to protect the body 

 from the freezing cold. 



To keep the water out of the lungs when diving, the blow- 

 holes are provided with valves that, like a cork in a bottle, 

 close more firmly the greater the pressure outside. 



the lunge, which, cooling, changes to vapor, and in its circling descent resembles a 

 shower of spray. 



* The tail has often an area of 100 square feet, is exceedingly flexible, and so 

 strong that the whale can spring clear out of the water " like little fish leaping into 

 the air after flies," falling again to the sea with a crash that is heard for miles. 



t In other animals, as the hog, the fat lies between the skin and the muscles. 



\ The whale often descends to the depth of a mile, where, according to Scoresby, 

 the pressure upon it is equal to 200,000 tons, and wood becomes so watersoaked as 

 not to rise again. 



This enormous bulk of fat is lighter than the water and gives great buoyancy, 

 BO that the dead body of a whale floats until the layer of blubber is u flensed off," 

 when it sinks. 



