ARCTIC ZOOLOGY. 113 



and subjected nearly to similar temperature, approximate 

 surprisingly in constitution. The Greenlander bleeds pro- 

 fusely from the nose, if no accident aiford the salutary 

 evacuation in any other mode, during the active and 

 dangerous season of the summer ; nor does he consider 

 the loss of blood on such occasions an injury. Wound a 

 seal about the same time, that is, before he becomes ex- 

 hausted by the natural occupations of the season, and 

 the profusion of arterial blood is astonishing for the size 

 of the animal. The whale is an extraordinary proof of the 

 accumulation which this portion of vital matter may attain 

 in an animal's frame. 



Early writers on natural history have drawn conclu- 

 sions as to the prolongation of life, which they would re- 

 present as indispensable in circulation of the blood. If an 

 animal, according to such opinion, is obliged to Hve in 

 water, and occasionally to respire atmospheric air, some pe- 

 culiar organization of the heart becomes a necessary means 

 of explaining the phenomenon. What may be the proper 

 agency of the heart in the circulation of the blood, most 

 probably will long remain to be explained. This is ap- 

 plied to the received opinion that a passage in the heart, 

 called the foramen ovale, is essential to the continuation 

 of life in such animals as dive long and frequently under 

 the surface of water. The seal is made a memorable in- 

 stance of this necessary conformation of that viscus as 



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