Section 149. The rabbit, together with the hares and conies, rats and mice, voles, squirrels, beavers, cavies, guineapigs is included in that order of the class of mammals which is called the rodentia, and is distinguished by the character of the incisor teeth from other orders of the class. 10. _Questions and Exercises_ 1. Describe the venous circulation of the rabbit (with diagrams). Compare a vein and artery. Compare the distribution of the great venous trunks with that of the arterial system. 2. Construct a general diagram of the circulation of the rabbit, to show especially the relation of the portal system, the lymphatics and lacteals, and the renal circulation to the main blood current. 3. Draw the alimentary canal of the rabbit from memory. 4. What is a villus? Describe its epithelium, and the vessels within it. Write as explicit an account as you can of the absorbent action of a villus. 5. Tabulate the alimentary secretions, and their action on the food. 6. What is botryoidal tissue? Where does it occur? What is known of its functions? 7. Copy Diagram I. (enlarged), and insert upon it the visceral nerves as far as you can. 8. What are the most characteristic points in the mammalian vertebral column? 9. Describe cartilage and bone, and compare them with one another. 10. Give an account of the amoeba, and compare it with a typical tissue cell in a metazoon (e.g., the rabbit). 11. Give a general account of connective tissue. What is tendon? 12. Trace, briefly, the increased modification of tissues in the vertebrata. 13. Describe, with diagrams, the structure of blood. State the function of each factor you describe. 14. Compare the pectoral with the pelvic limb and girdle. What other structures of the adult rabbit display a similar repetition of similar parts? 15. Draw from memory typical vertebrae from each region of the vertebral column. 16. What are bilateral symmetry and metameric segmentation? 17. Give a schedule of distinctive mammalian features. 18. Describe the rabbit's brain (with diagrams). 19. Give a list of the cranial nerves of the rabbit, and note their origin in the brain. 20. Give a list of the nerve apertures of the dog's skull. 21. What are the chief anatomical differences between a typical cranial, a spinal, and a sympathetic nerve? 22. Describe and figure the distribution of nerves V., VII., IX., and X. 23. Describe the muscles, glands, and nerves of the orbit of the rabbit. 24. Describe, with figures, the eye of the rabbit. 25. Give a diagram of the rabbit's internal ear. 26. Draw and describe the ear ossicles. What is their function? 27. Draw and state the precise position of the hyoid bone, the clavicle, the calcaneum, and the olecranon process. 28. Describe, as accurately as possible, the position of palatine bones, pterygoids, the ethmoid bone, the pre- and basi-sphenoids, in the dog's skull. 29. What is membrane bone? What is cartilage bone? Discuss their mutual relationship.