

CHAPTER IV. 



STRUCTURE OF THE HUMAN BODY CONTINUED. 



1. ANOTHER form of cellular structure is called fibrous, 

 from the arrangement of its component parts, which consist 

 of longitudinal fibres, plainly visible to the naked eye, placed 

 parallel to each other and closely united. These fibres are 

 sometimes so combined as to form a thin, smooth, dense, and 

 strong membrane, like that which covers the external surface 

 of bones, termed periosteum, or the internal surface of the 

 skull, (dura mater.) At other times it forms a firm sheath, 

 which dips down between the muscles, separating them from 

 each other, or it may be spread over them, binding them 

 firmly down in their placejk 



2. In the loins and along the back bone there is a strong 

 binder of this kind, which greatly facilitates the motions of 

 the body and powerfully contributes to the action of the 

 muscles. Where this is weak, a belt round the waist is of 

 considerable service, but in a well-formed person it is a 

 clumsy substitute of art for nature, and ultimately tends to 

 weaken the back, for exercise strengthens and invigorates all 

 parts of the frame, while artificial substitutes invariably 

 weaken the parts they are supposed to strengthen. 



3. It also constitutes the strong, tough, and flexible band, 

 used for tying parts firmly together, termed ligaments, such 

 as are found about the joints, connecting the bones ) and it 

 also forms those white cords in which muscles terminate, 

 called tendons, which serve to attach the muscles to the 

 bones, thus acting as mechanical instruments of motion. 

 This tissue forms a firm covering or envelope to the bones, 

 muscles, tendons, cartilages, the eye, kidneys, spleen, and 

 most of the organs of the body. 



