INDEX 



265 



Nestlings, 14, 101-103, 159, 160, 241 

 Nests, of birds, loi, 149-152, 158 



fishes, 135 



mammals, 176 



spiders, 122 

 Newts, 2, 15, 17, 70, 184 

 Night, effect on carnivores, 213 

 Nightjars, 154 

 Nilgai, 91 

 Nipple, 189, 243 

 Noiotrema, 142 



Oil-beetle, 33 



Operations on animals, 189 



Opossum, 181 



Orang, 7, 38, 194, 201, 208, 241, 253 



Organs, larval, 234 



Oribi, 89 



Orioles, in 



Oryx antelope, 89 



Osprey, 105 



Ostrich, coloration of chick, 104 



duration of youth, 49 



eggs of, loi 



food of young, 161 



longevity of, 49 



presence of quills, 97 



sexual coloration 69 



South American, 105 

 Otoliths of fish, 52 

 Otter, 42, 87 

 Ovary of fishes, 138 

 Oven-birds, 148, 151 

 Ovipositor, 124, 127, 138 

 Owls, 49, 102, 105, III, 149, 153 

 Oxygen, 234 

 Oyster, 63, 129 

 Oyster-catcher, 79 



Paints, scaling, 8a 

 Paludina, 130 

 Pampas deer, 92 

 Panda, 87 

 Pangolin, 179 

 Parasites, 58, 82, 192 

 Parasitism, 149 

 Parental care, 118, 161, 262 

 Parr, 52 



Parrots, 49, 64, 100, 102, iii, I49> 153. 



161 

 Partridges, 106, 108 

 Pattern, in animals, 63 



in birds, 112 



conspicuous, 75 



growth, 81 



of mammals, 81, 96 



origin of, 1 13 



primitive, 113 



as repetition of parts, 64 



rupture, 78, 96 



secant, 78 



spotted, 81 



striped, 81 



of young animals, 224 

 Peacock, " eyes " in tails, 76 



pheasant, 71 



sexual coloration, 69 

 Peat-moss, 193 

 Peccaries, 45, 171, 184, 218 

 Peckham, Mr. and Mrs., 235 

 Peewit, 99 

 Pelage, 87, 96 



Pelicans, 49, 104, no, 153, 162' 

 Penguins, 63, 97, 102, 104, 107, no, 149, 



153. 157 

 Perennibranchs, 60 

 Performing animals, 312 

 Pets, 213, 216 

 Petrels, loa, 149, 154, i6a 

 Phalarope, 70, 109 

 Pheasants, 69, 71, 106, 108, 241 

 PhoUs, 135 

 Phototaxis, 232 

 Phototropism, 232 

 Phyllomedusa, 141 



Pigeons, 49, 101-103, in, 150, 153, 163 

 Pigments, 66, 154 

 Pigs, 46, 93, 164, 171, 175 

 Pike, 233 

 Pipe-fish, 137 

 Placenta, 138, 139 

 Plant -lice, 54 



Plants, reaction to light, 232 

 Platypus, 2 

 Plovers, 102 



Plumage, breeding, 99, 112 

 coloration of, 104 



