526 



INDEX. 



Fish, fresla-water, distribution of, 



406. 

 Fishes, ganoid, now confined to 



fresh water, 98. 



, electric organs of, 178. 



, ganoid, living in fresh 



water, 351. 

 , of southern hemisphere, 



399. 

 Flat-fish, their structure, 220. 

 Flight, powers of, how acquired, 



166. 

 Flint-tools, proving antiquity of 



man, 16. 

 Flower, Prof., on the Larnyx, 



225. 



, on Halitherium, 357. 



, on the resemblance between 



the jaws of the dog and Thyla- 



cinus, 441. 

 Flower, Prof., on the homology 



of the feet of certain mar- 

 supials, 451. 

 Flowers, structure of, in relation 



to crossing, 86. 

 , of compositse and umbelli- 



ferae, 137, 205. 



, beauty of, 191. 



, double, 271. 



Flysch formation, destitute of or- 

 ganic remains, 320. 

 Forbes, Mr. D., on glacial action 



in the Andes, 396. 



, E., on colors of shells, 127. 



, on abrupt range of shells in 



depth, 161. 

 , on poorness of palseonto- 



logical collections, 319. 

 , on continuous succession of 



genera, 346. 

 , on continental extensions, 



382, 383. 

 , on distribution during Gla- 

 cial period, 390. 

 , on parallelism in time and 



space, 426. 

 Forests, changes in, in America, 



69. 

 Formation, Devonian, 361. 



, Cambrian, 339. 



, intermittent, 328, 



Formations, thickness of, in 



Britain, 317. , 

 Formica, rufescens, 255. 



, sanguinea, 256. 



, flava, neuter of, 273. 1 



Forms, lowly organized, long en 



during, 118. 

 Frena, ovigerous, of cirripedes, 



176. 

 Fresh-water productions, dis- 

 persal of, 405. 

 Fries, on species in large genera 



being closely allied to other 



species, 54. 

 Frigate-bird, 169. 

 Frogs on islands, 413. 

 Fruit-trees, gradual improvement 



of, 31. 



in United States, 48. 



, varieties of, acclimatized in 



United States, 135. 

 Fuci, crossed, 387, 293. 

 Fur, thicker in cold climates, 127. 

 Furze, 457. 



Galapagos Archipelago, birds of, 

 411. 



productions of, 417, 419. 



Galaxias, its wide range, 406. 



Galeopithecus, 165. 



Game, increase of, checked by 

 vermin, 65. 



Gartner, on sterility of hybrids, 

 279, 280, 284. 



, on reciprocal crosses, 286. 



, on crossed maize and ver- 



bascum, 304. 



, on comparison of hybrids 



and mongrels, 306, 307. 



Gaudry, Prof., on intermediate 

 genera of fossil mammals in 

 Attica, 357. 



Geese, fertility when crossed, 283. 



, upland, 169. 



Geikie. Mr. , on subaerial denuda- 

 tion, 316. 



Genealogy, important in classifi- 

 cation, 435. 



Generations, alternate, 456. 



Geographical distribution, 373. 



Geography, ancient, 503. 



