LIST OF ILLUSTRATIONS. xix 



FIG. PAGE 



342. Urogenital organs of male rabbit ..... 692 



343. Urogenital organs of female rabbit ..... 692 



344. Segmentation of rabbit's ovum (Van Beneden) . . . 701 



345. Development of hedgehog. Three early stages (Hubrecht) . 702 



346. Embryo of Perameles with its foetal membranes (Hill) . . 703 



347. Two stages in segmented ovum of hedgehog (Hubrecht) . 704 



348. Development of foetal membranes (Hertwig) . . . 705 



349. Diagram of foetal membrane (Turner) .... 706 



350. View of embryo, with its foetal membranes (Kennel) . . 709 



351. Pectoral girdle of Echidna . . . . . .716 



352. Pelvis of Ech idna . . . . . . . .718 



353- Urogenital organs of male duckmole (Owen) . . . 719 



354. Urogenital organs of female duckmole (Owen) . . .719 



355. Lower jaw of kangaroo ....... 721 



356. Foot of young kangaroo ....... 725 



357. Hmd-foot of OK . 732 



358. Fore-leg of pig . .... 732 



359. Side view of sheep's skull, with roots of back teeth exposed 733 



360. Stomach of sheep (Leunis) 734 



361. Side view of calf s fore-leg . ...... 735 



362. Side view of lower part of pony's fore-leg .... 737 



363. Side view of ankle and foot of horse ..... 737 



364. Side view of horse's skull, roots of teeth exposed . . 738 



365. Feet of horse and its progenitors (Neumayr) . . . 739 



366. External appearance of common porpoise .... 744 



367. Left fore-limb of Balcenoptera ...... 745 



368. Fore-limb of whale (Megaptera longimana] (Struthers) . 745 



369. Pelvis and hind-limb of Greenland whale (Balcena) (Struthers) 746 



370. Vertebra, rib, and sternum of Bahenoptera .... 748 



371. Skull of tiger, lateral view . ...... 750 



372. Lower surface of dog's skull ...... 751 



373. The common seal ........ 756 



374. Skeleton of fox-bat (Pteropus} ...... 760 



375. Skull of Orang-Utan 768 



376. Skull of gorilla 769 



377. Skeleton of male gorilla ....... 770 



378. Diagram showing hypothetically the action of natural 



selection in the evolution of a white race of mice from 



a dark-coloured stock (Schonichen) . . . .811 



