KNOX ON THE CETACEA. 



Contributions to the Anatomy and Natural History of the 

 Cetacea. By E Knox, Esq., M.D., F.E.S.E. Communi- 

 cated by the Secretary. 



[Eeceived Oct. 6, 1857.] 



Part I. The Dolphins. 



The dissection of the Cetacea, and more especially of the larger 

 kinds, is attended with great difficulty, and not unfrequently 

 entails heavy expenses on those who attempt it. For these 

 reasons I have thought that zoologists might be pleased to have, 

 even now, submitted to them the results of numerous dissections 

 made many years ago, when, not stinted in means, and having the 

 aid of excellent assistants, I attempted the dissection even of the 

 gigantic Arctic Rorqual, the largest, perhaps, of all living beings. 

 Certain of the details have been from time to time laid before the 

 public, but in an extremely scattered and incomplete form, and 

 without the illustrations (artistic), which explain so much better 

 than any verbal description. The greater part is still before me 

 in manuscript. It is my intention in the following contributions 

 to endeavour to connect them together, adding to those already 

 published many facts I find in MSS. The original drawings, 

 made by my brother and by Messrs. Edward Forbes and Henry 

 Goodsir (who were at that time my students and assistants), are 

 still in my possession. 



Determination of Species. — The determination of species as 

 regards the Cetacea is one of much difficulty ; Cuvier met this 

 difficulty by an appeal to anatomy. The number of vertebrae com- 

 posing the vertebral column (exclusive of the cephalic) seemed to 

 me a tolerably secure guide in the determination of species, — being 

 aware, however, that some doubted the method, believing that the 

 number of the vertebrae might vary, first, with the individual, 

 secondly with the age of the specimen. I still continue to be of 

 my original opinion, that the number of vertebrae comprising the 

 vertebral column, properly so called, may safely be trusted in de- 

 termining the species of the Cetacea ; and with this view I drew 

 up the following Table, excepting from it the genus Dugong, which 

 I have never considered to be a Cetacean : — 



LINN. PROC— ZOOLOGY. 5 



