1534 Cetacea. 



that anything can be decided on this subject, which is one of very 

 great difficulty, as well as interest. 



The distance of the pectoral fins from the posterior angles of the 

 mouth, might be supposed as varying with the greater or lesser dilata- 

 tion of the folded thoracic membrane; but it is evident that the only 

 effect, if any, produced on the anterior limbs, would be a vertical, and 

 not a horizontal change of position. 



I maintain that the colouring of the characteristic folds does not 

 vary with age, and from the same motive stated when speaking of the 

 baleen, that age and size have not the slightest relation with 

 the colouring, which is constant. The red maculation of the up- 

 per lip has never been found on any other species than the ones which 

 I regard as identical with the specimens noticed by myself. 



The number of vertebrae is not yet sufficiently well ascertained to 

 allow of its being employed as a good character, but it is exceedingly 

 improbable that this number should be as variable as has generally 

 been supposed, for a skeleton must have been prepared with the ut- 

 most negligence to have lost as many as seventeen vertebrae ; and 

 forty-eight to sixty-three vertebrae, are numbers too different to be 

 supposed to exist in an)' one species of Mammalia. 



I believe I may affirm, that no other placental animal produces 

 young (one in number), which, at their birth, would be as small as 

 those of the Northern Baleinopterae considered as one species : the 

 measurements of specimens of all sizes, from ten feet to a hundred 

 and twenty, having been recorded in different works. 



All the preceding remarks may, without any doubt, be criticised, 

 and most likely will be, but I doubt whether they will be easily re- 

 futed : if they only serve to attract the attention of some naturalist to 

 this interesting subject, I shall deem myself happy to have given 

 rise to new observations, which to be useful must be detailed and 

 correct. 



After all, is it not better to adopt a species too many, than to abo- 

 lish one on insufficient grounds ? In the first case, a simple notice of 

 the error, when discovered to be really such, mends the harm for ever ; 

 whilst in the latter case, a fact is entirely lost, and a link is missing in 

 the chain, or a mesh in the great net of the " Natural System." 



The characters I have made use of are entirely external ; the inte- 

 rior parts having seldom been described, it is next to impossible to 

 make use of them specifically at present, but I intend on a future oc- 

 casion publishing my observations on this subject. 



1 shall now say a few words concerning the animal which induced 



