5. (a) What are the protovertebrae? (b) How does the notochord originate in the frog? (c) How are the vertebrae laid down in the tadpole? (d) Describe the vertebral column of the adult frog. (e) In what important respects do the centra of the vertebrae of the frog, the dog-fish, and the rabbit differ from one another? 6. Give an account of the more important features in the development of the frog. 7. What temporary organs are developed in the embryo frog which are absent from the embryo bird and mammal, and what in the two latter which are absent from the former? 8. Draw diagrams, with the parts named, of the heart and great arteries of the frog, giving descriptions only in so far as is necessary to explain your diagrams; trace the development of these structures in the tadpole; point out particularly in which of the embryonic visceral (branchial) arches the great arteries of the adult run. 9. Trace the history of the post-oral gill-slits and their accompanying cartilaginous bars and vascular arches in the frog, fowl, and rabbit. 10. Give a short account, with illustrative figures, of the mode of formation of the primary germinal layers in amphioxus and in the frog. What explanation can you give of the differences between the two cases? 11. Give a short account, with diagrammatic figures, of the principal changes which occur in the circulatory and respiratory organs during the metamorphosis of the tadpole into the frog. 12. How do protozoa differ from higher animals (metazoa) as regards (a) structure, (b) reproduction? Compare the process of fission in an amoeba with the segmentation of the ovum in amphioxus, pointing out the resemblances and differences between the two cases. -Miscellaneous Questions_ [Most of these questions were actually set at the Biological Examinations of London University.] {In Both Editions.} 1. Describe (a) the digestive, (b) the circulatory, (c) the excretory, and (d) the reproductive organs of the amphioxus. 2. Describe the stomach and intestines of the dog-fish and rabbit, and point out in what way their differences are connected with diet. 3. Describe the mechanism of respiration in the adult frog, and contrast it with that of the tadpole. 4. Give an account of the structure of the epidermis and its outgrowths in the frog and the rabbit. 5. Describe the organs of circulation (heart and main arteries and veins) and respiration in the frog in its mature and immature states. 6. Give a brief account of the physiology of respiration. Describe fully the means by which respiration is effected in the following animals:-- frog, amphioxus, rabbit, and dog-fish. 7. Describe the minute structure of the blood of the rabbit, frog, and amphioxus. 8. Describe and illustrate by means of sketches the chief points of difference between the skeleton of the rabbit as a typical mammal, and that of the common frog as a typical amphibian.