spnimairenient , Texistence des plexus artériels dont noii^s par- 

 lons. Bien que tout ce qu'il dit soit exact, sa description est,p£ff 

 trop laconique et devient insuffisante. Il fait provenir ces plexp? 

 des artères intercostales et de Tarière sous-clavière ,,avan.t,s.ç>n 

 p^gs^gesur la pveBaière côte (1); il se borne à des indiçatipjtiu^fpiii- 

 rement anatomiques , et ne sWrète sur aucune considération to^r 

 cfeiant les fonctions, de masses vasculaires aussi considérables ('2). 

 Il fait remarquer que les cétacés ont une énorme quantité: de 

 sang ; que , pour contenir ce liquide, il fallait non-seulement des 

 artères d'un gTand calibre, mais encore un grand nombre d^ 

 Itranches latérales pour recevoir ce sang, et que dans le ca-r 

 c^!^^^ot Faorte a un pied de diamètre. Thus the heai-t aiid aoiia of 

 spermaceti-whale appeared prodigioiis , being too large tu be cohtj 

 tained in tJie widç tub, the aorta measiifitig a foot in dianieter. 



(1) «Animais of ihe tribe, as bas been observed, bave a greater proporiion of blood 

 than any otber known, and Ihere are maoy arteries apparently intended as reserr 

 voirs, ^\here a larger qiiantity of aiteral blood seeoicd lo be requiied in a part, 

 and vascularity could nol bc tbe only objecl. Tluiswe find, ihat the intercostal al- 

 iènes dtvide in(o a vast number of branches, which run in a serpentine 

 course between the, pleura, ribs, and their muscles, making a tbick substance 

 somewhat similar to thaï formed by the spermaiic artery in the buU. Tbose vessels, 

 every where lining the sides of the thorax, pass in between the ribs ncar their arti- 

 culation, and also behind the ligamentous aitachmentof the ribs, and anastomose 

 with eacholher. The medulla spinalis is surroundcd whith net-work of arteries in 

 the same manner raore especially where it cornes out froni tlie brain, where a 

 thickisubstance is formed by their ramifications and ronvolutions; and thèse 

 wessels most probably anastomose with those of the thorax. » 



Observationson ihe structure and Econoniy of the AVhales. 

 P^Ups. trqnsapt., vol. 77, p. 371, aunik-1787. 



(2) The use of which we do nol readily see. 



