Marshall, 124-125. Martens, von, 102. Mauritius, fighting cocks, 97, 106. Mechanism, 277. Meckel, 208. Mesoderm, 193, 194. Metridium, 104. Michel, 190, 192. Minchin, 105. Minimal size, 55-57. Molgula manhattensis, 237. Mollusks, 104. Morgan, 9, 30, 32, 33, 43, 44, 57-62, 64, 65, 68, 126, 131, 175, 185, 186, 187, 225, 231, 232, 237, 238, 243, 246, 247, 248, 249, 268. Morphallaxis, 13, 270-271. Mosses, 16, 17. Moulds, 16. Mouse, 178. Mucor mucedo, 86. Müller, E., 112. Müller, Fritz, 100, 213. Mus decumanus, 178. Mus sylvaticus, 178. Muscles, 114, 116, 120, 128, 181. Myriapods, 100, 104; autotomy, 154. Nägeli, 278, 280. Nais, 104, 146. Natural selection, 96, 108-110, 155-157, 262, 290, 292. Necturus, 106. Nematodes, 104. Nemerteans, 104, 143. Nereis, 143. Nerves, 114. Nervous system, 114. Newport, 100, 154. Nothnagel, 116, 117, 120. Nucleus, influence of, 66, 67, 258, 281. Nussbaum, 20, 66, 202, 203. Oblique surface, 44-52, 281. Oka, 210. Old part, influence of, 62-65. Oligochæta, 143. Ontogeny, 212-215, 282. Organization, 251, 275, 277, 278, 279, 288. “Origin of Species,” 109. Ovary, 124. Oxygen, influence of, 36, 77-78. Palla, 66. Palolo, 143. Paramœcium, 103. Parypha, see Tubularia. Pathological Regeneration, 21. Peebles, F., hydra, 27, 56, 63, 101, 167, 168. Peipers, 113. Pekelharing, 118. Pennaria tiarella, 35. Petromyzon, 105. Pflüger, 216, 242-243, 246, 252, 256, 264, 265, 288. Phagocata, 104. Phallusia mammalata, 236. Phasmids, 154. Phialidium variabile, 142. Phillipeaux, 112, 200. Phoxichilidium maxillare, 102. Phylogeny, 212-215. Physa, 104. Physiological Regeneration, 19, 25, 128-131. Pizon, 210. Planaria lugubris, see Planarian. Planaria maculata, see Planarian. Planaria torva, 26. Planarian, 9, 11, 13, 27, 28, 29, 40, 41, 43, 44-51, 64-65, 104, 107, 129, 133-135, 136, 141, 142, 201, 207, 273, 280. Planorbis, 104. Plants, 15, 70-91. Plasomes, 278. Platodes, 104. Plethedon cinereus, 201. Pliny, 1. Podocoryne, 103, 168. Podwyssozki, 113. Poisons, 123. Polarity, 38-40, 43, 177, 277, 280. Polychæta, 143. Polyclads, 104. Polyzoa, 149. Ponfick, 111. Populus dilatata, 75, 76, 80. Post generation, 20; criticism of, 20 (footnote); 216, 219-221. Pringsheim, 17, 86. Proglottids, 146. Proteus, 106. Protozoa, 103, 145. Przibram, 63, 100, 213. Purpose, 282, 283. Qualitative division of nucleus, 263. Rabbit, 112, 113, 117, 118, 179. Rana esculenta, 184. Rana palustris, 185. Rana virescens, 185. Rand, 124, 164. Randolph, 136, 190, 194. Rat, 113, 179. Rathburn, 153. Rauber, 263-264. Réaumur, 1; experiments with worm and with hydra, 2; 92, 151. Recklinghausen, 118. Regeneration, definition of, 19-25; incomplete, 125. Regular Regeneration, 25. Regulation, 22. Remak, 208. Reparation, 22. Restitution, 22. Restorative Regeneration, 25. Rhabdocœlous, Planarians, 142, 149. Ribbert, 112, 115, 117, 179-181. Rievel, 190.