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MANUAL OF ZOOLOGY. 



radius and ulna are followed by the bones of the wrist, which 

 are usually composed of several bones, and constitute what is 

 called the carpus (d). These support the bones of the root of 

 the hand, which vary in number, but are always more or less 

 cylindrical in shape. They constitute what is called the meta- 

 carpus. The bones of the metacarpus carry the digits, which 

 also vary in number, but are composed each of from two to 

 three cylindrical bones, which are known as the phalanges (p). 

 Homologous parts are, as a rule, readibly recognisable in the 

 hind-limb. The pelvic arch, by which the hind- 

 limb is united with the trunk, consists of three 

 pieces the ilium, ischium, and flukes which are 

 usually anchylosed together, and form conjointly 

 what is known as the innominate bone (fig. 243, i). 

 In most Mammals, the two innominate bones 

 unite in front by ligamentous or cartilaginous 

 union, and they constitute, with the sacrum, 

 what is known as the pelvis. The hind-limb 

 proper consists of the following parts : i. The 

 thigh - bone or femur, corresponding with the 

 humerus in the fore-limb. 2. The bones of 

 the shank (or " crus "), corresponding with the 

 radius and ulna of the fore-limb, and known as 

 the tibia and fibula. Of these, the tibia is 

 mainly or altogether concerned in carrying the 

 foot (or "pes"), and it is thus shown to corre- 

 spond to the radius, whilst the fibula corresponds 

 to the ulna. 3. The small bones of the ankle, 

 known as the tarsus, and varying in number in 

 different cases. 4. A variable number of cylin- 

 drical bones (normally five), which are called 

 the metatarsus, and which correspond to the 

 metacarpus. 5. Lastly, the metatarsus carries 

 the digits, which consist of from two to three 

 of Chim anzee sma ^ bones or phalanges, as in the fore-limb. 

 {after Owen), i The digestive system of Vertebrates will be 

 / n Fe a ortH n g e h: spoken of at greater length hereafter; but a 

 bone ; / Tibia ; s brief sketch may be given here of the general 



Fibula; r Tarsus; , _ <.. 9 . .. ,, , 



m Metatarsus ; p phenomena of digestion. All Vertebrate ani- 

 Phaianges of the ma i s are p rov ided with a mouth for the recep- 

 tion of food, and in the great majority of cases 

 the mouth is furnished with teeth, which are used sometimes 

 merely to hold the prey, but more commonly to cut and bruise 

 the food, and thus render it capable of digestion. The food is 

 also generally subjected in the mouth to the action of " saliv- 



Fig. 243. Pelvic 

 limb (hind -limb) 



