220 VERTEBRATE ANIMALS. 
the cervical region (fig. 117, c), comprising a variable number of 
vertebree, which constitute the neck, and immediately follow 
the head. Secondly, the cervical region is succeeded by a 
variable number of vertebrae which usually carry ribs, and are 
known as the dorsal vertebre (d), or vertebrae of the back. 
Thirdly, come certain vertebree which constitute the /wmbar 
region (4), or the region of the loins. Fourthly, there usually 
follows a series of vertebrae which are 
immovably united together to form a 
single bone, which is termed the sacrum 
(s). Lastly, there comes avariable series 
of vertebrze which are usually free and 
movable upon one another, and which 
constitute the caudal region, or the 
region of the tail (Z). 
The nature of the bones which enter 
into the composition of the limbs varies 
somewhat in different Vertebrates in 
accordance with their mode of life; 
but in all the higher members of the 
sub-kingdom the limbs are built upon 
a general and easily recognisable type. 
The fore-limb consists generally of the 
following parts: 1. A series of bones 
uniting the limb to the trunk, the two 
most important being the shoulder- 
blade (scafula) and the collar-bone 
(clavicle) (fig. 118, sandc). 2. The bone 
which forms the upper portion of the 
limb proper, and which is known as the 
humerus (h). 3. Two bones which form 
the lower portion of the limb (e.g., the 
Wig. 118.—Fore-limb of the +. arm in man), and which are known 
Chimpanzee. c Collar-bone, ; 
or clavicle:sShoulder-blade, aS the radius and ulna (r and x), of 
or scapula; % Bone of the which the former is the bone mainly 
pte iic teas 7 concerned in carrying the hand or fore- 
the wrist, or carpus; 7 Bones foot. 4. A number of small bones, which 
of the root of the hand, or form the wrist, and are termed the 
( ee ofthe carpus (a). 5. The cylindrical bones 
(usually five in number) which form 
‘the root of the hand, and are known as the metacarpus (m). 
Hy He 
Tad Hi] 
7 20. LY 
