CONTENTS. 



- LESSON II. 



THE SKELETON IN GENERAL. THE INTERNAL SKELETON, THE 

 BACKBONE, BREASTBONE, AND RIBS. Pp. 22 73. 



I. The skeleton generally. 



2. The exo- and endo-skeletons. 



3. The endo-skeleton. 



4. The joints. 



5. The divisions of the endo-skeleton. 



6. The backbone composed oi" vertebrae. 



7. Their different categories. 



8. A dorsal vertebra. 



9. A cervical vertebra. 



10. The axis. 



1 1. The atlas. 



12. The lumbar vertebrae. 



13. The sacrum. 



14. The coccyx. 



15. The backbone as a whole. 



1 6. The breastbone. 



17. The ribs. 



18. Development of the spinal endo-skeleton. 



19. Relations with other animals as to general structure. 



20. As to numbers. 



21. As to categories. 



22. Relation of form and condition generally. 



23. As to dorsal vertebrae. 



24. As to cervical vertebrae. 



25. As to lumbar vertebrae. 



26. As to the atlas. 



27. As to the axis. 



28. As to the sixth and seventh vertebrae. 



29. As to the sacral vertebrae. 



30. As to the coccygeal vertebrae. 



31. As to the spine in general. 



32. As to modes of ossification. 



33. As to the thorax. 



34. As to the sternum. 



35. As to the ribs. 



36. As to development. ; 



