tive streak?

3. Describe the cleavage and the surface appearances of the egg of
the frog and of the rabbit, up to the time when the first gill-slits
appear in the embryo. Give illustrative diagrams of what you
describe.

4. Describe the structure and cleavage of the ovum (a) of the frog, (b)
of the fowl, and (c) of the rabbit. (d) Explain as far as possible the
differences in the cleavage of these three eggs. (e) Point out how the
embryo is nourished in each case, and (f) describe the constitution of
the placenta in the rabbit.

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 c