PREHENSION IN ANIMALS. 197 



also prehensile, or hand-like, in its action, though it is a foot in structure ; 

 hence the use of the term Quadrumanous is not anatomically, though it is 

 teleologically, correct. In the lemurs, the hand is distinctly locomotive, as 

 well as simply prehensile ; the thumb is here wanting. 



Next to the monkej^s and lemurs, a prehensile power is manifested in the 

 limbs of the Carnivora, especially in the feline tribe, in which the hinder, as 

 well as the fore-limbs, are both prehensile and locomotive. In the hinder limb, 

 however, the phalanges of the lirst or inner toe are absent, and the first meta- 

 tarsal bone is rudimentary. There is a special contrivance in all four limbs of 

 the cat tribe, by which the last phalanx, which is curved, and provided with 

 a bony sheath for the firm attachment of the hooked claw, can be withdrawn, 

 or protruded, at the pleasure of the animal. At the inner side of the last 

 phalanx but one, is a lateral process, or projection, upon which the last pha- 

 lanx plays ; certain elastic ligaments, passing from one to the other, keep the 

 claw habitually retracted, without effort on the part of the animal, and thus 

 out of the way, in ordinary locomotive acts ; but the powerful flexor muscles" 

 of the last phalanges move the claws forwards, and so protrude them, when 

 the feet are used for prehensile purposes, as in climbing, or in holding prey, 

 or in acts of offence and defence. It is obvious that these retractile claws are, 

 in this way, saved from unnecessary wear, and are not protruded to the incon- 

 venience of the animal in simple locomotion. A certain power of pronation 

 and supination of the fore paw, is permitted in these animals, by a mpderate 

 rolling movement of the radius on the ulna ; but this is not to be compared 

 with what is found in the apes and monkeys, in which it equals that possessed 

 by man. In the bears, a greater amount of pronation is permitted than in 

 the cats. 



The prehensile power of the limbs, in animals lower than the Carnivora, 

 begins to disappear, first from the hinder limb, and then from the fore limb 

 also ; the squirrel and the kangaroo have already been mentioned, but with 

 these, and a few other like exceptions, the fore limb comes to be used perhaps 

 as a burrowing, or climbing, member, but more commonly as a locomotive 

 organ of some kind or other ; and the prehensile faculty of the animal is exer- 

 cised either by the lips and jaws, or else, as in the case of the elephant's pro- 

 boscis, which possesses not less than 40,000 separate interlacing muscular 

 slips, by a special muscular organ provided for that purpose. The tail also, 

 in certain Quadrumana, as in the spider-monkey, which has no thumb in the 

 hand, is a prehensile organ of great length and power. In accordance with 

 the adaptation of the fore limb to purposes of locomotion only, the movements 

 of pronation and supination between the radius and ulna, are absent in the 

 Kuminants, Solipeds, Cetaceans, and others. In the mole, the burrowing 

 power of the fore limb is provided for, by the shortness and width of the hu- 

 merus, radius, and ulna, by the limitation of the movements at the shoulder 

 and elbow, and by the presence of a curious sickle-shaped bone, situated be- 

 tween the radius and the base of the thumb, which serves to increase the 

 width of the strong hand. In this animal also, the clavicle is strong, is artic- 

 ulated in a peculiar manner, and has a very large subclavius muscle attached 

 to it. 



The characters and structure of the prehensile organs in Birds, viz., the 

 bill and jaws, and the feet and claws, do not require special explanation ; 

 neither do those of the powerful prehensile jaws and teeth of the dolphins and 

 porpoises, amongst the Cetaceous mammalia ; nor of the large Saurian Eep- 

 tiles ; nor of the sharks, and other predaceous Fishes ; nor yet the feebler in- 

 struments of the soft-skinned Amphibious Animals and the smaller Fishes. 

 The tongue, in the parrots, is large, and acts against the upper jaw, in hold- 

 ing and turning the food ; in the honey-feeding humming-birds, the tip of the 

 tongue is filamentous ; in the woodpecker, its point is barbed. The tongues 

 of the woodpecker, chameleon, and toad, likewise, aiford examples of special 

 contrivances for the prehension of food, each possessing the power of being 

 suddenly protruded and withdrawn again into the mouth. In the wood- 

 pecker, the tongue is supported on a hyoid, or lingual bone, which is bifurcated 

 backwards, and extended, by cartilaginous prolongations, along two grooves 

 on the back of the cranium ; these prolongations being drawn forward in the 



