BOOK I. 



LocoMOTORY Apparatus. 



The locomotory apparatus is composed of all those organs which minister to the 

 movements an animal may execute. It is certainly one of the most important in 

 the economy, from the niunber and size of the pieces which enter into its 

 formation, and by the necessary co-operation it affords the majority of the other 

 apparatuses in the performance of the physiological acts allotted to them. 



It is constituted of two kinds of organs— the bones and muscles. The lones^ 

 hard and resisting, stony in appearance, are really inert levers, joined by firm 

 and movable articulations, which permit their playing upon each other with the 

 greatest facihty, at the same time maintaining them in their relative positions. 

 The muscles, grouped around the bones and attached to them, are soft organs 

 which possess the property of contraction, under certain determinate conditions, 

 and of involving in that movement the bones to which they are fixed by their 

 extremities. The bones are altogether passive in their motion, while the muscles 

 are really the active organs of locomotion — the power intended to move the bony 

 levers. 



We will study, successively — 



1. The bones, a particular branch of descriptive anatomy which has received 



the name of Osteology ; 



2. The articulations, or Arthrology ; 

 8. The muscles, or Myology. 



FIRST SECTION. 

 The Bones. 



CHAPTER I. 

 THE BONES IN GENERAL. 



Bones, properly speaking, are only to be found in vertebrate animals, and 

 constitute their principal zoological chara«ter. In the animal body they form 

 an internal framework which consolidates the entire edifice, and gives it its 

 general form and dimensions. It is advantageous, before commencing a particular 

 description of each bone, to survey them in a general manner. This study 

 comprises: 1. The description of the skeleton; 2. A summary indication of 



