SYSTEM OF ANATOM>Y. 



PART I. 



OSTEOLOGY. 



CHAPTER I. 



GENERAL ANATOMY OF THE OSSEOUS SYSTEM. 



Classification and structure of bones Chemical composition Recent researches 

 on the intimate structure of bone Periosteum Medullary membrane Car- 

 tilages Formation of bone Terms used in describing bones. 



THE osseous tissue in man and nearly all large animals 

 not inhabiting a dense medium, constitutes that scaffolding 

 or framework, upon which is supported all the soft parts of 

 the body. Hence the bones when seen in connexion in a 

 perfect skeleton, present so perfect an outline of the animal to 

 which they belonged, as to be sufficient as has been shown by 

 Baron Cuvier, to indicate clearly its shape, size, and mode of 

 life as well as the nature of the food upon which it lived.* 

 The bones may be considered* as designed for the fulfilment 

 of two principal objects the formation of cavities for the 

 protection of delicate and important organs, as in the head, 

 thorax, and pelvis and of columns and levers for support and 



* A skeleton, or a structure. analogous to it in its uses, that of forjpng a 

 foundation upon which the body can be built, and to which the muscles may be 

 attached in order to move it from place to place, is found in the mammiferae, 

 birds, and many fishes, in the interior of the body ; in the Crustacea and teslacea, 

 some fish, reptiles, &c., it is wholly or in part at the exterior. In a great 

 majority of cases it is bony in its structure ; it is, however, cartilaginous in 

 many fishes, and fibrous in nearly all coleopterous insects, of which it forms 

 the external covering. p. 



