18. Is living bone sensitive? Ans.—Scrape a bone, and its vessels bleed; cut or bore a bone, and its granulations sprout up; break a bone, and it will heal; cut a piece away, and more bone will readily be produced; hurt it in any way, and it inflames; burn it, and it dies. Take any proof of sensibility but the mere feeling of pain, and it will answer to the proof.—BELL'S Anatomy. Animal sensibility would be inconvenient; it is therefore not to be found except in diseased bone, where it sometimes exhibits itself too acutely.—TODD'S Cyclopedia of Anatomy.
19. Is the constitution of bone the same in animals as in man? Ans.—The bones of quadrupeds do not differ much from those of man. In general they are of a coarser texture, and in some, as in those of the elephant's head, we find extensive air cells.—TODD'S Anatomy.
II.
THE MUSCLES.
"Behold the outward moving frame,
Its living marbles jointed strong
With glistening band and silvery thong,
And link'd to reason's guiding reins
By myriad rings in trembling chains,
Each graven with the threaded zone
Which claims it as the Master's own."
HOLMES.
ANALYSIS OF THE MUSCLES.
| 1. The Use of the Muscles. | 2. Contractility of the Muscles. | 3. Arrangement of the Muscles. | 1. THE USE, STRUCTURE | 4. The two Kinds of Muscles. | AND ACTION OF THE | 5. The Structure of the Muscles. | MUSCLES. | 6. The Tendons for Fastening Muscles. | | 7. The Muscles and Bones as Levers. | | 8. The Effect of Big Joints. | | 9. Action of the Muscles in Walking. | |10. Action of the Muscles in Walking. | | 2. THE MUSCULAR SENSE. | | 3. HYGIENE OF THE | 1. Necessity of Exercise. | MUSCLES. | 2. Time for Exercise. | | 3. Kinds of Exercise. | | 4. WONDERS OF THE MUSCLES. | | | 1. St. Vitus's Dance. | | 2. Convulstions. | | 3. Locked-jaw. |5. DISEASES. | 4. Gout. | 5. Rheumatism. | 6. Lumbago. | 7. A Ganglion.
FIG. 14.
[Illustration]