106 
ANATOMY AND PHYSIOLOGY 
This rete mirabile , as it has been termed by Mr, 
Owen, has, since the time of Hunter, been noticed by 
Drs. Barclay and Knox, and by Desmoulins and 
Breschet, in France ; but the use of this remarkable 
structure has not yet been clearly ascertained, although 
Sir William Jardine, in the Nat, Lib. vol. vL p. 50, 
has with “ considerable hesitation 55 attempted the ex- 
planation of this ({ extraordinary phenomenon. 55 
“ No circumstance,” he remarks, “ connected with 
the economy of whales, is more extraordinary than the 
long period during which they can suspend the vital 
function of respiration . 5? 
Respiration is in a great degree subservient to the 
circulation of the blood ; the stimulus to inspiration is 
the accumulation of this fluid in the lungs, which when 
purified proceeds to the heart, whence it is propelled 
through the frame for the purposes of secretion, etc. ; 
after which it is again received into the veins, where it 
assumes its venous aspect, and is deprived of its arterial 
character. The circle thus described in man and the 
mammalia generally, is, so to speak, continuous and 
simple. In the cetacea, however, it is not so ; for in 
them the arterial portion, insteadjof being a simple and 
direct course to the venous, is complicated by the 
addition of a structure which we believe is peculiar to 
this order, and which is nothing less than a grand 
reservoir for the reception of a great quantity of arterial 
blood, which, as occasion requires, is emptied into the 
general circulation, and thus for a time at least super- 
sedes the necessity of respiration. 55 
