of the Greenland Whale. 15 



l^e found the principal artery of the body to measure n6t less 

 than three feet in circumference, and that it received from ten 

 to fifteen gallons of blood at every pulsation of the heart. 

 Therefore, as Dr. Kidd has observed, if we consider the heart 

 of the whale not to exceed twenty pulsations per minute, at 

 this rate of fifteen gallons received by the artery at every pul- 

 iation, we find, that not less a quantity than four hundred and 

 thirty-two thousand gallons, or eight thousand hogsheads of 

 blood, do literally pass through the heart of a whale during 

 every twenty-four hours of the creature's existence. 



I may, however, observe, that my friend. Dr. James Alder- 

 son, who has more recently had an opportunity of examining 

 the heart of the same species of whale as the one to which Mr. 

 Hunter alluded, although he found the aorta to be of equal 

 size, supposes that the capacity of the left ventricle was not 

 equal to the reception of more than eight or ten gallons of 

 blood. 



The heart of the whale, although much flattened, presents, 

 otherwise, no important deviation in its structure from that of 

 terrestrial quadrupeds ; but, like that of other diving mammalia^ 

 and of the seals which I described on a former occasion, it is 

 connected with an enormous development in the arterial and 

 venous systems, in order to preserve it free from the oppres- 

 sion which would otherwise be occasioned by the returning 

 blood ; thereby to extend the intervals between respiration : 

 to this end, the vessels, in various parts of the body, as Mr. 

 Hunter observed, form, by their innumerable tortuous subdivi- 

 sions, vast spongy receptacles ; and, in other situations, the 

 trunks themselves seem to be proportionately much enlarged. 

 The proportionate quantity, also, of blood, in the whale, as in 

 the seal, appears to be far greater than in land animals, which 

 is, indeed, the case in all the aquatic mammalia. 



I recollect having been surprised by an observation of an 

 old Greenland captain, that the blood of all the animals of 

 high northern latitudes was of a much darker colour than in 

 those of more southern regions ; it being, he remarked, in many, 

 almost black ; he alluded, especially, to the aquatic mammalia, 

 which fell most under his observation, and such is literally the 

 case in them. I have since observed the same fact to obtain 



