XIII. — OSTEOLOGY OR SKELETONS. 105 



Collar Bones {Clavides)-\ on each side 2 



Shoulder Blades {Scapulce)—! on each 



side 2 



Arm Bones {Humerus, Ulna, Radius) — 



3 in each arm 6 



Hand — Wrist or Carpal Bones, 8; 

 Metacarpal Bones, 5 ; Thumb, 3 ; 

 Fingers, 4, with 3 Bones each = 12; 

 making 27 in each hand 54 



Pelvis or Hip Bones— 1 on each side 



(in the young in 3 pieces, anchylosed 

 with age) 2 



Leg Bones {Femur, Tibia, Fibula, 



Patella or knee cap) — 4 in each leg 8 



Foot — Ankle, 7; Metatarsus, 5; Great 

 Toe, 2 ; other Toes, 4, with 3 Bones 

 each = 12 j making 26 in each foot. .. 52 



Total separate Bones 180 



The characteristic Bone is the Back Bone. It is composed of 

 a number of separate bones called Vertebrae, which are shaped 

 something like rings, and are placed one against another with an 

 elastic tissue uniting them. They are hard and massive in 

 front, but thin behind, with sharp processes or points projecting 

 and forming a line down the back — hence the name spine. 

 Together they form a long tube which, in the living animal, 

 contains the spinal marrow. It is from this that the sub- kingdom 

 Vertebrata takes its name. 



The Skull consists of 22 bones, which in infancy are separate, 

 but in youth become dovetailed together and united so firmly 

 as to practically form one piece. In one of the Cases is' ex- 

 hibited a disarticulated skull showing the shape and position of 

 these separate bones. The interior of the skull is occupied by 

 the Brain, and is called the " Brain Cavity." The Cranium or 

 Skull consists properly of 8 bones, but there are 14 Bones of the 

 Face attached to it and usually spoken of as forming part of it. 

 The Lower Jaw is attached by a joint, but does not form part of 



