M. Madeira, wingless beetles of, 68-70; peculiar beetles of, 226, 227. Mammals, ovum of, 120-124; embryology of, 151-155; palæontology of, 163, 165, 167, 180-199; limbs of, 174-178, 182-199; brain of, 194-199; of Australia and New Zealand, 204, 205; distribution of, on islands, 224-240. Mammoth cave, fauna of, 70-72. Man, nictitating membrane of, 75; vestigial muscles of, 76, 77, 82, 83; tail of, compared with that of apes, 82-84; hair of, compared with that of apes, 89-92; teeth of, compared with those of apes, 92-94; perforation of humerus of, 94, 95; flattening of ancient tibiæ of, 95, 96; embryology of, 119, 153; hand of, 54; arm of, 90, 91; limb-bones of, 176, 177; palæontology of, 163, 165; brain of, 194, 195; Mr. Syme on, 346, 347. Marsh, on palæontology of the horse, 188-190. Matthew, Patrick, on natural selection, 257. Mesoderm, 142. _Mesohippus_, 189, 192. Metaphyta, 104, 105. Metazoa, 104. Method, ideas of, in natural history, 1-9; of organic evolution, 252-261. Meyer, Professor Ludwig, on helix of the human ear, 86. Mimicry, 320-322. Ministration, mutual, of species alleged, 445, 446. _Miohippus_, 189. Mivart, St. George, on eye of octopus, 57, 58, 348, 349; on incipient organs, 362; on mutual ministration of species, 445, 446. Mollusca, shells of, 19, 199-203; eye of, 57, 58; embryology of, 155; palæontology of, 163, 165. Monkeys, why all, do not become men, 342-344. _Monotremata_, 205. Morgan, _see_ Lloyd Morgan. Morphology, 50-97. Mule, portrait of, 309. Multicellular organisms, 104. Multiplication, _see_ Reproduction. N. Nägeli, Prof., 337, 367. Natural History, ideas of method in, 1-9. Natural, interpretations as opposed to super-natural, 13-15; causation, 13-15. Natural selection, 252-378, 401-410; Wells, Matthew, and Whewell on, 257, 258, 443-445; statement of theory of, 256-284; of evidences of, 285-332; of criticisms of, 333-378; relation of theory of, to religious thought, 401-410; preserves types, 264-267; cessation and reversal of, 270, 342; errors touching theory of, 270-284, 332-364; definition of, 275-376; antecedent standing of theory of, 277-284; Prof. Owen on, 333, 334; Duke of Argyll on, 334-362; Mr. Syme on, 340, 341, 345; need not always make for improvement, 341-347; homology and analogy in relation to, 347-350; often determines beauty, 406, 407; in relation to the formation of galls, 293-295. 446-448. Nature, organic, 17; inorganic, 1, 17, 18. _Nauplius_, 138. Neumayr, 19. New Zealand, fauna of, 68, 204, 205; thriving of exotic species in, 286. Newman, on the Illative Sense, 6. Newton, his idea of scientific method, 6. Nictitating membrane, 74, 75. Notochord, 146. Novum Organon, the, on scientific method, 2. Nucleus, 105, 112-134. Nucleus-spindle, 129. Nut-hatch, Syrian, ornamented nests of, 381. O. Objective methods, 6. Oceanic islands, _see_ Islands.