OP THE CETACEA. 51 



then described it as existing AAdtliin the spinal canal 

 of the white whale; more lately, Dr. Knox has 

 observed it within the cranial cavity itself; whilst 

 Messrs. Desmoulins and Breschet have noticed it in 

 France. In a few words, we may describe it as a 

 great irregular reservoir of arterial blood, contained 

 "vvithin a plexus of arteries, deriving its blood from 

 the vessels near the heart, which lines a large por- 

 tion of the interior of the chest, insinuating itself 

 between the ribs, fonning a great cushion external 

 to them near the spine, and also within the spinal 

 canal and the cranium itself. Now it is this struc- 

 ture which we believe has been, and which we 

 would venture again to adduce, as offering a satis- 

 factory explanation of the extraordinary fact under 

 review. None of the authors named above have 

 associated this remarkable structure with the no 

 less remarkable phenomenon*; nor have they as- 

 signed any other use to it. It would appear that 

 these great vessels, or cyhnders, as Mr. Hunter calls 

 them, do not communicate directly with veins; 

 nor are they formed of ramifications which commu- 



* Since writing the above, we have met with M. Dumeril's 

 Report (Ann. des Sc. Nat., 1834) of M. Breschet 's Paper on 

 the Vascular System of the Cetacea, which bears the title of 

 a Discovery in the Circulation, affecting the respiration of this 

 order. We have in vain attempted to procure the Memoir 

 itself. It was on the testimony of the Cyclopedia of Ana- 

 tomy and Physiology for May, 1836, p. 577, that we stated 

 that Mr. B.'s memoir contained "no facts or physiological 

 inferences additional to M. Hunter's paper." The discovery 

 as to the structure is certainly and clearly no discovery at all ; 

 but it appears to us that iM. Breschet has the merit of first 

 assigning to it its true and very important use. 



