ON THE ORIGIN OF SPECIES BY MEANS OF NATURAL SELECTION, OR THE PRESERVATION OF FAVOURED RACES IN THE STRUGGLE BY CHARLES DARWIN, M.A., FELLOW OF THE ROYAL, GEOLOGICAL, LINNEAN, ETC., SOCIETIES; "But with regard to the material world, we can at least go so far as this-we can perceive that events are brought about not by insulated interpositions of Divine power, exerted in each particular case, but by the establishment of general laws." WHEWELL: Bridgewater Treatise. "The only distinct meaning of the word 'natural' is stated, fixed, or settled; since what is natural as much requires and presupposes an intelligent agent to render it so, i.e. to effect it continually or at stated times, as what is supernatural or miraculous does to effect it for once." BUTLER Analogy of Revealed Religion. "To conclude, therefore, let no man out of a weak conceit of sobriety, or an ill-applied moderation, think or maintain, that a man can search too far or be too well studied in the book of God's word, or in the book of God's works; divinity or philosophy; but rather let men endeavour an endless progress or proficience in both." BACON Advancement of Learning. Down, Bromley, Kent, October 1st, 1859. (1st Thousand). CHAPTER VI. Difficulties on the theory of descent with modification-Transitions-- Absence or rarity of transitional varieties-Transitions in habits of life-Diversified habits in the same species-Species with habits widely different from those of their allies-Organs of extreme perfection-Means of transition-Cases of difficulty- Natura non facit saltum-Organs of small importance—Organs not in all cases absolutely perfect-The law of Unity of Type and of the Conditions of Existence embraced by the theory of Domestic instincts, their origin - Natural instincts of the cuckoo, ostrich, and parasitic bees Slave-making ants - Hive-bee, its cell-making instinct - Difficulties on the theory of the Natural Selection of instincts - Neuter or sterile insects - Summary Distinction between the sterility of first crosses and of hybrids - Sterility various in degree, not universal, affected by close inter- breeding, removed by domestication-Laws governing the sterility of hybrids — Sterility not a special endowment, but incidental on other differences - Causes of the sterility of first crosses and of hybrids - Parallelism between the effects of changed con- ditions of life and crossing - Fertility of varieties when crossed and of their mongrel offspring not universal - Hybrids and mongrels compared independently of their fertility - Summary |