Limbs of Vertebrate Animals. 29 



nail of the 3rd or middle finger in man of that ringer, the 

 dominance of which, even in man, is indicated by its 

 greater size and length. And this is all that need be 

 said upon this point at present save this, that the 

 hind foot is a repetition of the fore foot with this sole 

 difference that the 'canon bone' there corresponds, 

 not to the metacarpal bone, but to the metatarsal. 



The fin of the dugong (Manatus) is to all intents 

 and purposes a hand enclosed in a fingerless glove of 

 integument through which the nails have worked their 

 way a little. It differs very slightly from the webbed 

 hand or foot of the seal or otter : it does not differ at 

 all in the number of bones or joints composing it ; and 

 the difference between it and the paddle of the turtle or 

 whale or ichthyosorus, or between it and the fin of a 

 fish, is not at all considerable. The paddle of the 

 turtle, in fact, is so much like that of the sirenian 

 animal as to need no special notice. The paddle of the 

 whale has more than the ordinary number of phalanges 

 in the fingers, and the various bones of the hands are 

 connected, not by proper joints but by continuous inter- 

 articular cartilages : and what is said of this organ may 

 also be said of the pectoral fin of the fish, for this 

 member differs from the paddle chiefly in having many 

 more fingers with many more phalanges, and in being 

 constructed more delicately. In each case, indeed, 

 there is that repetition of simple parts that ' vegetative 

 repetition ' as it is called which is a sign of that 

 rudimentary phase of development to which the state 

 of the joints also bears witness, for the formation of 

 the true joint, as in the paddle of the dugong, is 

 always preceded by a state in which the parts are con- 

 nected by inter-articular cartilage, as in the paddle of 

 the whale. In some cases, too, the real relationships of 



