THE SEA-LION 



287 



most of them have what is called an " interfemoral 

 membrane,'' that is to say, a membrane which extends 

 inwards on either side from the leg, and embraces the 

 tail. The seal therefore may also be said to possess an 

 " interfemoral membrane," though the influence it exerts 

 is exercised in aquatic and not aerial locomotion. 



Seals would be exceedingly numerous but for their 

 constant destruction by man. What this must be is 

 indicated by the fact that two hundred thousand indivi- 

 duals of the kind known as " the Greenland seal," are 

 annually killed around Jan Mayen Island in the North 



Fig. 75. 



THE GREENLAND SEAL. 



Sea, by the crews of Scotch, Dutch and Norwegian 

 vessels. Seals — that is "true seals" as distinguished 

 from sea-lions — are naturally inhabitants of all the 

 shores of the temperate and colder regions, and one kind 

 found north of the Equator is also found south of it, 

 yet, with one exception, not even a single genus is 

 common to the northern and southern hemispheres. 



Many kinds of seals are gregarious, but others are 

 solitary, and all are harmless animals to man if not 

 attacked. They are very fond of basking in the sun- 

 shine, and spend a large part of their time on sand-bars, 

 rocks, or on the ice, according to circumstances. They 



