ONONIS. 



INDEX. 



PLANTS. 



333 



Ononis, small imperfect flowers of, 



1. 269. 

 Orchids, fertilisation of, i. 241. 

 , the development of their 



tlowers, i. 303. 



, forms of, ii. 216. 



Orchis, pollen of, i. 236. 

 Organisation, tendency to advance, 



i. 151. 

 Organs of extreme perfection, i. 223. 



, electric, of flsheB, i. 234 



of little importance, L 245. 



, homologous, ii. 233. 



, rudiments of, and nascent, ii. 



255. 

 Ornithorhynchus, i. 130 ; ii. 208. 



, mammae of, i. 296. 



Ostrich not capable of flight, i. 281. 

 , habit of laying eggs together, 



i. 335. 

 , American, two species of, ii. 



132. 

 Otter, habits of, how acquired, i. 



216. 

 Ouzel, water, i. 222. 

 Owen, Prof., on birds not flying, L 



167. 

 , on vegetative repetition, i. 



184. 

 , on variability of unusually 



developed parts, i. 185. 



, on the eyes of fishes, i. 227. 



, on the swim-bladder of fishes, 



i. 231. 

 , on fossil horse of La Plata, ii. 



96. 



, on generalized form, ii. 107. 



. , on relation of ruminants and 



pachyderms, ii. 107. 

 , on fossil birds of New Zea- 

 land, ii. 121. 



, on succession of types, ii. 121. 



, on affinities of the dugong, ii. 



206. 



, on homologous organs, ii. 233. 



, on the metamorphosis of oe- 



phalopods, ii. 244. 



Pacific Ocean, faunas of, u. 131. 



Pacini, on electric organs, i. 235. 



Paley, on no organ formed to give 

 pain, i. 254. 



Pallas, on the fertility of the domes- 

 ticated descendants of wild stocks, 

 ii.10. 



Palm with hooks, i. 247. 

 Papaper bracteatum, i. 272. 

 Paraguay, cattle destroyed by flies, 



i. 89. 

 Parasites, i. 334. 



Partridge, with ball of earth at- 

 tached to foot, ii. 148. 

 Parts greatly developed, variable, 



i. 185. 

 ParuB major, i. 220. 

 Passiflora, ii. 7. 



Peaches in United States, i. 104. 

 Pear, grafts of, ii. 18. 

 Pedieellariae, i. 298. 

 Pclagomium, flowers of, i. 180. 



, sterility of, ii. 7. 



Pelvis of women, i. 178. 

 Peloria, i. 180. 

 Period, glacial, ii. 151. 

 Petrels, habits of, i. 221. 

 Phasianus, fertility of hybrids, ii. 9. 

 Pheasant, young, wild, i. 329. 

 Pictet, Prof, on groups of species 



suddenly appearing, ii. 77. 



, on rate of organic change^ ii. 90. 



, on continuous succession of 



genera, ii. 93. 

 , on change in latest tertiary 



forms, ii. 71. 

 , on close alliance of fossils in 



consecutive formations, ii. 114. 

 , on early transitional links, ii. 



78. 

 Pierce, Mr., on varieties of wolves, 



i. 111. 

 Pigeons with feathered feet and skin 



Between toes, i. 14. 

 , breeds described, and origin 



of, i. 23. 

 , breeds of, how produced, i. 44, 



47. 

 , tumbler, not being able to get 



out of egg, i. 106. 



, reverting to blue colour, i. 197. 



, instinct of tumbling, i. 327. 



, young of, ii. 248. 



Pigs, black, not affected by the 



paint-root, i. 13. 

 , modified by want of exetcise, 



i. 249. 

 Pistil, rudimentary, ii. 266. 

 Plants, poisonous, not affecting cer- 

 tain coloured animals, 1. 13. 



, selection, applied to, i. 41. 



, gradual improveihent of, i. 42. 



, not improved in barbaroui 



countries, i. 43. 



