The geographical distribution of animals presents difficulties.--These not insurmountable in themselves; harmonize with other difficulties.--Fresh-water fishes.--Forms common to Africa and India; to Africa and South America; to China and Australia; to North America and {x} China; to New Zealand and South America; to South America and Tasmania; to South America and Australia.--Pleurodont lizards.--Insectivorous mammals.--Similarity of European and South American frogs.--Analogy between European salmon and fishes of New Zealand, &c.--An ancient Antarctic continent probable.--Other modes of accounting for facts of distribution.--Independent origin of closely similar forms.--Conclusion ... _Page_ 144 CHAPTER VIII. _HOMOLOGIES._ Animals made up of parts mutually related in various ways.--What homology is.--Its various kinds.--Serial homology.--Lateral homology.--Vertical homology.--Mr. Herbert Spencer's explanations.--An internal power necessary, as shown by facts of comparative anatomy.---Of teratology.--M. St. Hilaire.--Professor Burt Wilder.--Foot-wings.--Facts of pathology.--Mr. James Paget.--Dr. William Budd.--The existence of such an internal power of individual development diminishes the improbability of an analogous law of specific origination ... _Page_ 155 CHAPTER IX. _EVOLUTION AND ETHICS._ The origin of morals an inquiry not foreign to the subject of this book.--Modern utilitarian view as to that origin.--Mr. Darwin's speculation as to the origin of the abhorrence of incest.--Cause assigned by him insufficient.--Care of the aged and infirm opposed by "Natural Selection;" also self-abnegation and asceticism.--Distinctness of the ideas right and useful.--Mr. John Stuart Mill.--Insufficiency of "Natural Selection" to account for the origin of the distinction between duty and profit.--Distinction of moral acts into material and formal.--No ground{xi} for believing that formal morality exists in brutes.--Evidence that it does exist in savages.--Facility with which savages may be misunderstood.--Objections as to diversity of customs.--Mr. Button's review of Mr. Herbert Spencer.--Anticipatory character of morals.--Sir John Lubbock's explanation.--Summary and conclusion ... _Page_ 188 CHAPTER X. _PANGENESIS._ A provisional hypothesis supplementing "Natural Selection."--Statement of the hypothesis.--Difficulty as to multitude of gemmules.--As to certain modes of reproduction.--As to formations without the requisite gemmules.--Mr. Lewes and Professor Delpino.--Difficulty as to developmental force of gemmules.--As to their spontaneous fission.--Pangenesis and Vitalism.--Paradoxical reality.--Pangenesis scarcely superior to anterior hypotheses.--Buffon.--Owen.--Herbert Spencer.--Gemmules as mysterious as "physiological units."--Conclusion ... _Page_ 208 CHAPTER XI. _SPECIFIC GENESIS._