Mammalia or milk-givers, divisions of the, 182; distribution of, 340; aquatic, 300; extinction of large, 341; sudden appearance of higher, 211. Mammoth, the hairy, 279. Man, after Glacial Period, 343; _among animals now extinct_, 333; exterminating wild animals, 344. _Manatee or sea-cow grazing_, 315; relationship of, 303. Mandrill, the lowest baboon, 250. _Manis or pangolin_, 202; structure and habits of, 203. Marmosets, monkeys of South America, 245. Marmot, a burrowing rodent, 225. Marsh, Prof., his collection of reptile remains, 339; cited, 212; on Dinocerata, 260. Marsupials, jaws of earliest known, 183; breathing of infant, 192; of Australia, past history of the, 185; early appearance of, 337; playing the part of higher animals, 196; structure and habits of, 192–199. Mastodon, a four-tusked elephant, 279; _figured_, 256. Megalosaurus, 93; _figured_, 89. Megapodes, mound-building birds, 159. Megatheria, huge ancient ground-sloths, 202, 206, 208. Metamorphosis of the frog, 73–76. Mexico, iguanas of, 106. _Microlestes, tooth of_, 183. Migration, of birds, 142, 151, 155, 177, 348; of lemmings, 225. Milk-givers are viviparous, 185; earliest origin of, 191; extinction of large, 341; _home of the early_, 181; sudden appearance of higher, 211; taking to the water, 300. Miller’s thumbs, 65. Minnow, breathing apparatus of the, 22; _inner and outer structure of the_, 23–26; intelligence of, 26; spinal cord of, 23, 26. _Moa of New Zealand_, 140. _Mole_, 220; enemies of the, 224; structure and habits of, 223. Mole-rats, burrowing rodents, 226. Monitors of Africa, 105. _Monkeys_, 247; advantage of tree-life to, 251; almost confined to hot countries, 241; grasping hands and feet of, 241; intelligence of, 248; origin of, 240; of America, 245; of the Old World, characters of, 248. Monk-fish, 41. Moor-hen, intelligence of the, 151. Mosasaurus, 92; _figured_, 89. Motmots of America, 168. _Mound-building birds_, 158. Mucous scales of fish, 23, 27. Mud-fish and their breathing, 33. Mud-tortoises, 102. Mullets, feeding, 57. Musquash, a swimming rodent, 227. Myrmecobius, an insect-eating marsupial, 195; like the ancient marsupials, 198. _“Native Devil” or Dasyurus_, 197. Nervous system of vertebrata, 8. _Nest of the common wren_, 171; _of duck-billed platypus_, 188. Nest-building birds, 168–173; gradual progress of, 156, 160, 165, 167, 170, 173. Nests, edible, of China swiftlet, 167; inland, of wading birds, 151. _Newts_, 78. New Zealand, _wingless birds of_, 140. Nightjar hunting for prey, 167. Nile, _crocodile of the_, 108; mud-fish of the, 33. Norway, lemmings of, 225. Nostrils of fish, 27. Notochord of the lancelet, 12.