_Medusæ_, internal parasitism, 699. _Melanopsis recurrens_, from _Paludina_ bed, 275. _Menopoma_, characters of, 579. Mérian, Madame, figures of caterpillars referred to, 195, 232, 263, 268. Metagenesis, defined, 81, 96; derivation, 83. Metamorphosis, 430. Mexico, climate of, 619. Millière, figure of larva referred to, 254. Mimicry, 648, 663. Möller, L., phytophagic variability, 305. Mono- and digoneutic species, 16. Moore, F., figures of caterpillars referred to, 436, 526. Morris, affinities of _Apatura_ and _Nymphalis_, 438. Moths, seasonal dimorphism in, 4; resembling splinters, 292. Mühlenpfordt, on Lake of Mexico, 604. Müller, Fritz, odoriferous organs of butterflies, 102; sexual selection in butterflies, 103; habit and protective resemblance, 290; spiny caterpillars, 293; larva of _Papilio Evander_, 299; reversion in Orchids, 614; maggot-like larvæ of insects, 493; the biogenetic law, 611; mimicry, &c., 665. Müller, Hermann, larva of _Stauropus Fagi_, 290. Müller, P. E., _Leptodora hyalina_, 94. Murray, Andrew, seasonal change of colour, in animals, 7; green caterpillars, 293. _Muscidæ_, embryonic development, 492. N. Nägeli, reversion of cultivated plants, 107. Natural selection, 112, 361, 704, 705. Nature, mechanical conception of, 634; harmony of, 697. Neumayr and Paul, on _Melanopsis_, 275. _Noctuæ_, change of colour in larvæ, 166; number of legs in young larvæ, 166, 520; ontogeny of larvæ, 520. Noll, Dr., larva of _Ach. Atropos_, 324. North America, glaciation of, 622. Nurse-breeding in Hymenoptera and Diptera, 402. _Nymphalidæ_, larval classification, 435. O. Ontogeny, Fritz Müller and Haeckel on, 270; predominance of new characters in last stage of, 280, 283. Ontogeny and Phylogeny of Sphinx-markings, 177. Ophiuroidea, want of parallelism in, 396. Orchids, reversion in, 614. Organic compounds, synthesis of, 643. Organism, parts independently variable, 514. P. _Pachylia Ficus_, early stages of larva, 232. Packard, insect phylogeny, 493. Pangenesis, theory of, 668. _Papilio._ _P. Ajax_, seasonal forms, 30; _P. Turnus_, a dimorphic form, 32; _P. Machaon_ and _Podalirius_, seasonally dimorphic in Spain and Italy, 74; _P. Ajax_, experiments with, 126; _P. Merope_, young larva, 166; _P. Homerus_, young larva, 167; _P. Machaon_, larva rejected by lizards, 339. Parallelism, phyletic, in metamorphic species, 390; phyletic, law of, 510. _Pararga Ægeria_, sexually dimorphic, 68; climatic variation of, 68. Pascoe, F. P., “Zoological Classification” referred to, 488, 498. _Pelobates_, experiments with tadpoles, 607. _Pergesa Mongoliana_, larva, 194. _Philampelus achemon_ and _P. satellitia_, larvæ, 523; _P. labruscæ_, larva, 195; _P. vitis_, and _P. anchemolus_, larvæ, 232.