o 



70 Prof elisor Flower [May 25, 



freely movable at the shoulder-joint, where the humerus or upper- 

 arm bone articulates with the shoulder-bWle in the usual manner, 

 but beyond this point, except a slight flexibility and elasticity, there is 

 no motion between the different segments. The bones are all there, 

 corresjxjnding in numl>er and general relations with those of the 

 human or any other mammalian arm. but they are flattened out, and 

 their contiguous ends, instead of presenting hinge-like joints, come in 

 contact by flat surfaces, united t/-jgether by strong ligamentous bands, 

 and all wrapj>ed up in an undivided covering of skin, which allows 

 externally of no sign of the 6ej>arate and many-jointed fingers seen in 

 the skeleton. 



Up to the year 1865 it was generally thought that there was 

 nothin*^ to be found between this bonv framework and the covering 

 skin, with its inner layer of blubber, except dense fibrous tissue, 

 with blood-vessels and nerves sufficient to maintain its vitality. 

 Dissecting a large Rorqual, 67 feet in length, upon the beach of 

 Pevensey Bay in that year, I was surprised to find lying upon the 

 bones of the fore-arra well-developed muscles, the red fibres of which 

 reached nearly to the lower end of these h)ones. ending in strong 

 tendons, passing to. and radiating out on, the palmar surface of the 

 hand. Circumstances then prevented me following out the details 

 of their arrangement and distribution, but not long afterwards Pro- 

 fessor Struthers, of Aberdeen, had an opportunity of carefully dis- 

 sectinff the fore-limb of another whale of the same species, and he 

 has recorded and figured his observations in the 'Journal of Anatomy ' 

 for November 1871. He found on the internal or palmar aspect of 

 the limb three distinct muscles corresi>onding in attachments to the 

 flexor carj>i ulnaris, the flexor profundus dijritorum, and the flexor 

 longus pollicis of man, and on the opjxjsite side but one, the extensor 

 communis digitorum.* Large as these muscles actually are, yet, 

 compared with the size of the animal, they cannot but be regar^led as 

 rudimentary, and being attached to Ixjnes without regular joints and 

 firmly held together by unyielding tissues, their functions must be 

 reduced almost to nothing. But rudimentary as the muscles of the 

 Fin-whales are, lower staj/es of de^n^adation of the same structures are 

 found in other members of the group. In s^.»me they are indee^l 

 present in form, but their mascular structure is gone, and they are 

 reduced in most of the to^^thed whales to mere fibrous bands, scarcely 

 distinguishable from the surrounding tissue which c^^nnects the inner 

 surface of the skin with the Vjne. It is impossible to contemplate 

 these structure-s without having the conviction forced home that here 

 are the remains of parts once of use to their possessor, now, owing to 

 the complete change of purj^os^; and mode of action of the limb, reduced 

 to a condition of atrophy verging on complete disappearance. 



The changes that have taken place in the hind-limbs are even 



* The mmfflesi of the fore-arm fff an allied Hpecies, Jialmw/ptera rontraUj., were 

 descrflx^d by 3Iacaliister in 18€8, and Perrin in 1><70. 



