INVESTMENT 



MINUTE 

 STRUCTURE. 



Articular Carti- 

 lage. 



Periosteum , 



Haver sian Canals 



Lacunae 



THE COMPOSITION AND STRUCTURE OF BONE 45 



Covers articulating surfaces. 



Smooth. 



Covered with synovial membrane. 



Strong fibrous membrane. 



Covers the bone with the exception 



of articulating surfaces. 

 / About 5^5 in. in diameter. 



Run lengthwise through the compact 

 tissue 



Branched. 



Contain blood-vessels. 



Communicate with lacuna by means 



of canaliculi. 



| Surround Haversian canals in rings. 

 J Give off canaliculi in all directions. 

 ( Absorb and distribute nutriment. 



QUESTIONS ON LESSON VI. 



1. How would you remove the animal matter from bone, so as to obtain the 



mineral substance it contains ? 



2. How would you obtain gelacine from bone ? 



3. What is bone ash ? How would you obtain it ? 



4. How would you remove the whole of the mineral or earthy substance 



from a bone, in order to get the animal matter ? 



5. Describe the composition of bone. Do bones vary at all in composition ? 



If so, give illustrations. 



6. What are the differences between the bones of a young child, the bones of 



a middle-aged adult, and the bones of persons of extreme age ? 



7. Describe the different kinds of bones, pointing out their variations in 



structure. 



8. What is marrow ? WTiat is its use ? 



9. Compare the structure of the parietal bone with that of the femur. 



10. With what kinds of covering are bones invested ? 



11. How are bones supplied with blood ? 



12. Describe the minute structure of bone, as revealed by the microscope. 



Illustrate your description by sketches. 



LESSON VII. 

 THE MUSCULAR SYSTEM. 



BY removing the skin which forms the exterior covering of the 

 body, we expose to view masses of flesh or muscle (see fig. 3), 

 similar in appearance and structure to what we call lean meat, 

 which is really the muscle of the various animals used for food. 



The general character of muscle may well be studied by 

 examining a piece of beef. It is reddish in colour, but this is due 

 to the presence of blood, which circulates through every part of it. 



