G08 Description of a " White Fish,'' or " White Whaled 



at the apex are separated by a slight notch. The walls 

 of the cavities arc quite thin, and in drying diminished 

 very much less than those of the hearts of ordinary mam- 

 mals. The transverse and longitudinal diameters are 

 about one foot each. 



The ascending ao7'ta is largely dilated, having a diam- 

 eter of two and a half inches, becomes somewhat con- 

 tracted at the arch, and is again enlarged slightly after 

 giving off the left innominate artery, and then contracts 

 to about one inch in diameter. A dilatation similar to 

 that first mentioned, was noticed by Dr. Jackson in Pho- 

 cccna globiceps. Two innominate arteries are given off 

 from the arch of the aorta ; and the right subclavian, at 

 its origin, lies behind the carotid, instead of being on the 

 outside, as is usual among mammals. 



The great size and capacity of the heart, as well as of 

 the whole blood-system, is one of the most striking fea- 

 tures in the organization of cetaceans, and has often at- 

 tracted the attention of those who are in the habit of kill- 

 ing these animals, as well as of naturalists. The explana- 

 tion of the existence of so much blood we have not seen 

 offered, though we can hardly hesitate in supposing that 

 it is in some way connected with their aquatic habits. 



The faculty which whales have of withstanding the 

 effects of interrupted respiration is usually ascribed to the. 

 existence of a vascular net-work [rete mirabile) connected 

 with the intercostal vessels, which virtually forms a large 

 reservoir of arterial blood. From this the spinal marrow 

 derives its supply, and is thus kept in an active condition, 

 while other organs receive blood which is more venous. 

 While this explanation is doubtless correct as far as it 

 goes, it seems very probable that there is something be- 

 sides the conditions mentioned which tends to bring about 

 the same end, viz : the power of remaining for a long time 

 under water. 



