200 



INDEX 



Mosquito, female, 19, 64 



buzzing of, 127 



flight of, 129 



periodic activity of, 144 

 Moss, 172 



club-moss, 164 

 Moth, clothes, 64 



flour, 64 

 Moulds, 22 

 Mouse, food of, 81 

 Movement, of plants, 114-22 



of plants, how caused, 117 



sleep, 119 



amoeboid, 121 



of animals, 122 

 Mulberry, 164 

 Muscles, contraction of, 131 



relaxation of, 131 

 Mushrooms, 22 



Musk-ox, Ovibos moschatus, 78, 80 

 Musquash, 81 

 Mussel, 16, 58 



lines of concentric growth, 139 

 (fig. 49) 

 Myogenic theory, meaning of, 138 

 Myriapoda, 140 

 Myxomycetes, 9 

 fXy defined, 10 n. 



JSl EMATODA, see Roundworms 

 Nemertine worm, 108 

 Nephelis, 114 

 Nettle, stinging, 187 

 Newts, food of, 68 

 Nitrates, 33, 40, 89-90 

 Nitrites, 39 

 Nitrobacter, 39 

 Nitrogen, in protein, 7 



in protoplasm, 41 

 Nitrogen compounds, sources of, 37 

 Nitrogen cycle, 37, 42 

 Nitrosomonas, 39 

 Nitrous acid, 39 



Noctiluca, rhythmic brightness of, 135 

 Nodules, 38 

 NuceUus, 172, 174 

 Nucleus, 10 



of blood corpuscles, 108 



Odontisyllis ENOPLA, 146 

 Off -spring, number of, 175 



Oikomonas, rhythmic action of, 143 



Oikopleura, see Ascidians 



Oil, mineral, organic origin of, 34-5 



Old age, 191 



Operculum (gill-cover), 104 



Opossum, food of, 74 



Orange-juice, 95 



Orange tree, independent of seasons, 



148 

 Orang-utan, Simia satyrus, food of, 



85, 86 

 Orchids, number of seeds, 175 

 Orthonectid, 167 

 Osmosis, 48-9, 54, 55 

 Ostracoda, scavengers of sea, 66 



spermatozoa of, 184 



parthenogenesis of, 187 

 Ostrich, egg of, 183, 184 

 OtoHth, concentric rings in, 138 

 Oxygen, 7, 12, 28, 29, 99, 101, 110 



tension, 102, 114 



absorbed by muscles, 131 

 Oysters, Cicero on, 141 



change of sex of, 185 



J: ALOLO WORM, Eunice, spawn- 

 ing habits of, 145 



reproduction of, 164 

 Pancreas, 91, 92 



rhythmic action of, 137 

 Pancreatic juice, 91 

 Pap (bee), 62, 87 

 Paramoecium, 10, 123 



rhythmic motion of cells in, 133 



ciliary action of, 134 



conjugation of, 165, 189 



fission of, 190 

 Parasites, 18, 23, 24 

 Parthenogenesis, 186-91 



artificial, 190-1 

 Pasteur, 112 



Pearl, rhythmic growth of, 138, 139 

 Pecten, mode of swimming, 124 

 Pellagra, 94, 95 

 Perennial plants, 147 

 Peripatus, 182 

 Perissodactyla, 77 



food of, 78 

 Peristalsis, meaning of, 137 

 Periwinkles, influenced by tide, 144 

 Petrels, 72 



