THE LIVING MATERIAL OF THE BODY 



13 



joints. Sometimes it connects the bones, e. g. as it joins the 

 front ends of the ribs to the breast bones. Connective tissue 

 occurs throughout the whole body, binding together the dif- 

 ferent parts. A simple kind of connective tissue is seen in 

 beefsteak, where it appears in fine lines or as thin, glistening 

 sheets holding together the small cord-like pieces of muscle 

 tissue. More evident kinds of connective tissue are the liga- 

 ments and tendons; Fig. 2. Ligaments hold bones together 

 at joints, as at the knee or the shoulder. Tendons connect 

 muscles to bones, and may 

 plainly be felt at the wrist 

 where they pass from the 

 muscles in the forearm to 

 the bones in the fingers; 

 Fig. 137. It is said that 

 if all the other materials 

 of the body were dissolved 

 away and the connective 

 tissue left, this tissue is so 

 abundant that the form of 

 the body would be per- 

 fectly retained. 



Muscle tissue forms the 

 flesh and moves the differ- 

 ent parts of the body. 



Gland tissue composes 

 organs and surfaces which 

 generally produce some 

 fluid secretion, like the saliva in the mouth, the tears in 

 the eyes or the bile in the liver. 



Blood forms the so-called " circulating tissue." 



Nerve tissue is the material of which the brain and other 

 parts of the nervous system are composed. 



Fat tissue, while not active, serves to store material for 

 future use. 



FIG. 3. EPITHELIAL CELLS 



a, flat, scale-like cells from the mouth; 

 6, from the membranes around the 

 intestine; c, from the intestine; d, cili- 

 ated epithelial cells from the wind pipe. 



