Chapter CIII: Section 148: The rabbit shares with all mammals, and differs from all

other vertebrata (i.e., birds, reptiles, amphibia, and fishes), in having--

(a) Hair.

(b) A diaphragm.

(c) Only one aortic arch, and that on the left side of the body.

(d) Its young born alive. (But two very reptile-like mammals of
Australia, the duck-billed platypus and the echidna, lay eggs, and
certain fish and reptiles bear living young.)

(e) Epiphyses to its vertebral -centre- [centra].*

(f) The cerebral hemispheres covering the mid-brain.

(g) Corpora quadrigemina instead of bigemina.

[(h) A corpus callosum.]

[(i) A spirally coiled cochlea to the internal ear.]

[(In respect to h and i also, the echidna and platypus are scarcely
mammalinan.)]

* But certain mammals have no such epiphyses.