Messrs Cheek and Jones on the Anatomy of the Lion. 277 



Curiosit.) describes a peculiar articulation of the last phalanx of 

 the toes ; and, in fact, the nails are both retracted within a 

 sheath whilst walking, and peculiarly placed with relation to the 

 bones of the toes. 



To preserve the points of the claws constantly sharp, it is 

 necessary that they should not rub on the surface of the ground ; 

 and we consequently find them always directed with their points 

 upwards, and sunk in the hair on the upper surface of the toes. 

 Desmoulins thinks that this also contributes to the noiseless tread 

 of the animal. 



The means by which the claws are preserved in this state of 

 retraction during the passive condition of the animal, is not the 

 ieast remarkable part of the mechanism : by the disposition of 

 ligaments composed of the yellow elastic tissue, whose property 

 it is always to remain in a state of contraction, until acted on by 

 an extending force, the claws are constantly kept in this condi- 

 tion, except during the action of the flexor muscles. 



These ligaments were described* and figured by Perrault,f but 

 in an inaccurate manner, the extensor tendon of the joint being 

 mistaken for the retracting ligament of the claw. And as his 

 figure is associated with other inaccuracies in a publication 

 issued by the Society for the diffusion of Useful Knowledge, 

 before alluded to, we have thought that a correct diagram of 

 this beautiful mechanism would not be out of place, and would 

 at the same time interest those who admire the wonderful con- 

 trivances which are displayed in providing for the necessities of 

 living beings ; contrivances, of which this is a very striking 

 example, as being founded on a mere physical property of matter 

 supplying the place of a vital contraction, which the animal 

 would have been unable to maintain in permanent action. 



Fig. 1. 



In the annexed diagram. Fig. 1, in which the claw is extended 

 to shew the retracting ligaments, a represents the extensor 



* The description given by M. Cuvier of these ligaments is remarkably meagre 

 and incorrect. " Cette position reversee, dit-il, est celle du repos. La phalange 

 y est maintenue par deux sortes de ligamens : savoir la capsule articulaire, et deux 

 ligamens lateraux qui viennent de la seconde phalange. " — Anat. Comp. I. 31,2. 



f Memoires pour servir a I'Hist. Nat. des Animaux, 1758. 



