THE BONY FRAMEWORK 



A cylindrical bone is not weak although it is hollow. The 

 pillars of steel bridges, the posts for the support of electric 

 wires, and the frame of a bicycle are 

 made of hollow steel tubes. We all 

 know that stalks of grass and grain are 

 so light and slender that they will bend 

 before a light breeze, and yet they are 

 strong enough to bear their load of seed. 



Experiment 6. Saw in two, lengthwise, a 

 part of a beef shin bone, or a portion of a 

 sheep's or a calf's leg, including, if convenient, 

 the kneejoint. Boil, scrape, and carefully clean 

 one half. Note the compact and spongy bone, 

 the shaft, etc. 



Experiment 7. After the flesh has been cut 

 from the second half, note the pinkish white 

 appearance of the bone, the marrow, etc. Knead 

 a small piece of the marrow in the palm ; note 

 its oily appearance. Contrast this fresh bone 

 with an old, dry one picked up in the field. 



NOTE. While waiting for class use, fresh 

 bones should be kept in a cool place, carefully 

 wrapped in cloths moistened with listerine, dilute 

 carbolic acid solution, or even glycerin solution, 

 an ounce to one pint of water. 



28. The Shape of Bones. Bones are 

 of many different shapes, according to 

 the uses to which they are put. Some 

 are long, with hollow shafts, as the bones 

 of the arm and the leg; others are short 

 or irregular, to give strength, as the bones of the fingers, 

 the toes, and the spine. 



Some bones are flat, for protection and to cover cavities, 

 like the bones of the skull and shoulder blades ; while others 



FIG. 12. The Right 

 Femur sawed in 

 Two Lengthwise. 



Showing arrangement 

 of compact and 

 spongy tissue. 



