CHAPTER XXVII.—PROVISIONAL HYPOTHESIS OF PANGENESIS.
PRELIMINARY REMARKS—FIRST PART: THE FACTS TO BE CONNECTED UNDER A SINGLE POINT OF VIEW, NAMELY, THE VARIOUS KINDS OF REPRODUCTION—RE-GROWTH OF AMPUTATED PARTS—GRAFT-HYBRIDS—THE DIRECT ACTION OF THE MALE ELEMENT ON THE FEMALE—DEVELOPMENT—THE FUNCTIONAL INDEPENDENCE OF THE UNITS OF THE BODY—VARIABILITY—INHERITANCE—REVERSION—SECOND PART: STATEMENT OF THE HYPOTHESIS—HOW FAR THE NECESSARY ASSUMPTIONS ARE IMPROBABLE—EXPLANATION BY AID OF THE HYPOTHESIS OF THE SEVERAL CLASSES OF FACTS SPECIFIED IN THE FIRST PART—CONCLUSION.
DOMESTICATION—NATURE AND CAUSES OF VARIABILITY—SELECTION—DIVERGENCE AND DISTINCTNESS OF CHARACTER—EXTINCTION OF RACES—CIRCUMSTANCES FAVOURABLE TO SELECTION BY MAN—ANTIQUITY OF CERTAIN RACES—THE QUESTION WHETHER EACH PARTICULAR VARIATION HAS BEEN SPECIALLY PREORDAINED.
Figure 1. Dun Devonshire pony, with shoulder, spinal, and leg stripes. Figure 2. Head of Japan or masked pig. Figure 3. Head of wild boar, and of “golden days,” a pig of the Yorkshire large breed. Figure 4. Old Irish pig with jaw-appendages. Figure 5. Half-lop rabbit. Figure 6. Skull of wild rabbit. Figure 7. Skull of large lop-eared rabbit. Figure 8. Part of zygomatic arch, showing the projecting end of the malar bone of the auditory meatus, of rabbits. Figure 9. Posterior end of skull, showing the inter-parietal bone, of rabbits. Figure 10. Occipital foramen of rabbits. Figure 11. Skull of half-lop rabbit. Figure 12. Atlas vertebrae of rabbits. Figure 13. Third cervical vertebrae of rabbits. Figure 14. Dorsal vertebrae, from sixth to tenth inclusive, of rabbits. Figure 15. Terminal bone of sternum of rabbits. Figure 16. Acromion of scapula of rabbits. Figure 17. The rock-pigeon, or columba livia. Figure 18. English pouter. Figure 19. English carrier. Figure 20. English barb. Figure 21. English fantail. Figure 22. African owl. Figure 23. Short-faced English tumbler. Figure 24. Skulls of pigeons, viewed laterally. Figure 25. Lower jaws of pigeons, seen from above. Figure 26. Skull of runt, seen from above. Figure 27. Lateral view of jaws of pigeons. Figure 28. Scapulæ of pigeons. Figure 29. Furcula of pigeons. Figure 30. Spanish fowl. Figure 31. Hamburgh fowl. Figure 32. Polish fowl. Figure 33. Occipital foramen of the skulls of fowls. Figure 34. Skulls of fowls, viewed from above, a little obliquely. Figure 35. Longitudinal sections of skulls of fowls, viewed laterally. Figure 36. Skull of horned fowl, viewed from above, a little obliquely. Figure 37. Sixth cervical vertebræ of fowls, viewed laterally. Figure 38. Extremity of the furcula of fowls, viewed laterally. Figure 39. Skulls of ducks, viewed laterally, reduced to two-thirds of the natural size. Figure 40. Cervical vertebræ of ducks, of natural size. Figure 41. Pods of the common pea. Figure 42. Peach and almond stones, of natural size, viewed edgeways. Figure 43. Plum stones, of natural size, viewed laterally. FOREWORD