Chap. Y] THE SKELETON 51 



2 Clavicle 2 Tibia 



2 Humerus 2 Fibula 



2 Radius 10 Metacarpals 



2 Ulna 10 Metatarsals 



2 Femur 56 Phalanges 



90 

 Short bones. — The short bones are small pieces of bone ir- 

 regularly shaped. Their texture is spongy throughout, excepting 

 at their surface, where there is a thin crust of compact substance. 

 The short bones are the sixteen bones of the carpus, and the four- 

 teen bones of the tarsus. Some authors include the two patellae. 

 Flat bones. — Where the principal requirement is either exten- 

 sive protection or the provision of broad surfaces for muscular 

 attachment, the bony tissue expands into broad or elongated 

 flat plates which are composed of two thin layers of compact 

 tissue, enclosing between them a variable quantity of cancellous 

 tissue. 



The flat bones are as follows : — 



1 Occipital 2 Lacrimal 



2 Parietal 2 Scapula 



1 Frontal 1 Sternum 



2 Nasal 24 Ribs 



1 Vomer 2 Hip bones 



38 

 Irregular bones. — The irregular bones are those which, ok 

 account of their peculiar shape, cannot be grouped under either 

 of the preceding heads. 



The irregular bones are as follows : — 



24 Vertebrae 2 ]\Ialar 



1 Sacrum 2 Maxillse 



1 Coccyx 1 Mandible 



2 Temporal 2 Palate 



1 Sphenoid 2 Inferior turbinated 



1 Ethmoid J. Hyoid 



40 

 The bones of the ear are so small that they are described as ossicles 

 and do not fit in any of these groups. 



Processes and Depressions. — If the surface of any bone is 

 examined, certain projections and depressions are seen. The pro- 



