CARTILAGE CONNECTIVE TISSUE. 13 



part of the skeleton. United in various ways, they pro- 

 vide a strong framework which supports the softer 

 organs, and in some places, as the skull (Fig. 6) and 

 thorax (Fig. 5), make strong boxes or cages in which 

 delicate organs, such as the brain or lungs, lie safe. The 

 bones are also concerned in the movements of the body; 

 nearly all muscles pull first on some bone or other, and 

 when the bone is made to move, it of course carries with 

 it the surrounding soft parts. 



3. Cartilage is what we know in meat as gristle : it is 

 stiff enough to keep its shape, but can be bent with tol- 

 erable ease; it is also elastic, so that it springs back to 

 its proper shape, like a piece of whalebone, as soon as 

 the force which has bent it ceases to act. You can easily 

 feel on your nose the difference between bone and car- 

 tilage. The skeleton of that part of it near the forehead 

 is made of bone, and that of the lower part of cartilage. 

 We can push the tip of the nose to either side, or up and 

 down, but when we stop pressing, it returns to its place. 

 The skeleton of that part of the ear which projects from 

 the side of the head is also made of cartilage. 



Cartilage is used in parts of the skeleton which have 

 to be moderately stiff, but at the same time pliable and 

 elastic. 



4. Connective Tissue is used for several different pur- 

 poses in the body. To understand this, let us imagine 

 a quantity of very fine strands of silk, some twisted into 



3. What is cartilage ? Its properties? How used in the nose ? In 

 the ear ? Throughout the skeleton ? 



4. To what may connective tissue be compared ? Name and char- 

 acter of its threads ? How are the cords made? The membranes? 

 The loose portion ? Where do we find networks of connective tis- 

 sue? Give an example. 



