INDEX. 



453 



Ostrich, habit of laying eggs -.igether, 

 215. 



, American, two species of, 318. 

 Otter, habits of, how acquired, 138. 

 Ouzel, water, 142. 

 Owen, Prof., on birds not flying, 108. 



, on vegetative repetition, 118. 



, on variability of unusually 



developed parts, 119. 



, on the eyes of fishes, 145. 



, on the swim-bladder of fishes, 

 148. 

 — — , on fossil horse of La Plata, 

 294. 



, on generalized form, 301. 

 , on relations of ruminants and 

 pachyderms, 303. 

 — — , on fossil birds of New Zealand, 

 310. 



, on succession of types, 310. 

 , on affinities of the dugong, 

 365. 

 — — , on homologous organs, 383. 

 , on the metamorphosis of ce- 

 phalopods, 390. 



Pacific Ocean, faunas of, 317. 



Pacini, on electric organs, 151. 



Paley, on no organ formed to give 

 pain, 163. 



Pallas, on the fertility of the domes- 

 ticated descendants of wild stocks, 

 241. 



Palm with hooks, 158. 



Papaver bracteatum, 174. 



Paraguay, cattle destroyed by flies, 

 56. 



Parasites, 215. 



Partridge, with ball of earth attached 

 to foot, 328. 



Parts greatly developed, variable, 

 119. 



Parus major, 141. 



Passiflora, 238. 



Peaches in United States, 66, 



Pear, grafts of, 246. 



Pedicellaria?, 191. 



Pelargonium, flowers of, 166 



, sterility of, 239. 



Pelvis of women, 115. 



Peloria, 116. 



Period, glacial, 330. 



Petrels, habits of, 142. 

 Phaslanus, fertility of hybrids, 240. 

 Pheasant, young, wild, 211. 

 Pictet, Prof., on groups of species 

 suddenly appearing, 282. 



, on rate of organic change, 291. 



, on continuous succession cf 



genera, 293. 



, on change in latest tertiary 



forms, 278. 



, on close alliance of fossils in 



consecutive formations, 306. 



, on early transitional links, 283. 



Pierce, Mr., on varieties of wolves, 



71. 

 Pigeons with feathered feet and skin 

 between toes, 9. 



, breeds described, and origin of, 



15. 



, breeds of, how produced, 28, 



30. 



, tumbler, not being able to get 



out of egg, 68. 



, re-verting to blue colour, 127. 



, instinct of tumbling, 210. 



, young of, 392. 



Pigs, black, not affected by the paint- 

 root, 9. 



, modified by want of exercise, 



159. 

 Pistil, rudimentary, 397. 

 Plants, poisonous, not affecting cer- 

 tain coloured animals, 9. 



, selection "applied to, 27. 



, gradual improvement of, 27. 



, not improved in barbaro'.^ 



countries, 27. 



, dimorphic, 35, 253. 



, destroyed by insects, 13. 



, in midst of range, have to 



struggle with other plants, 60. 



, nectar of, 73. 



, fleshy, on sea-shores, 107. 



, climbing, 147, 196. 



, fresh-water, distribution of. 



345. 

 , low in scale, widely distri- 

 buted, 359. 

 Pleuronectidn?, their structure, 18G. 

 Plumage, laws of change in sexes of 



birds, 70. 

 Plums in the United States, 6Q. 

 Pointer dog, origin of, 25. 

 , habits of, 210. 



