INDEX 



343 



Forbes, E., on contiDuous succession 



of genera, ii. 100 

 , on continental extensions, ii, 



148-149 

 , on distribution during Glacial 



period, ii. 160 

 , on parallelism in time and space, 



ii. 209 

 Forests, changes in, in America, i. 



114 

 Formation, Cambrian, ii. 90 



, Devonian, ii. 120-121 



Formations, thickness of, in Britain, 



ii. 61 



, intermittent, ii. 75 



Formica rufescens, i. 364 



, sanguinea, i. 366 



, flava, neuter of, i. 388 



Forms, lowly organized, long endur* 



ing, i. 179 

 Frena, ovigerous, of cirripeds, i. 258 

 Fresh-water productions, dispersal of, 



ii. 180 

 Fries, on species in large genera being 



closely allied to other species, i. 94 

 Frigate-bird, i. 248 

 Frogs on islands, ii. 191 

 Fruir. trees, gradual im^Nrovement of, 



i. 65 



ill Dnited States, L 127 



, varieties of, acclimatized in 



United Slates, i. 202 

 Fuci, crossed, ii. 21, 29 

 Fur, thicker in cold climates, i. 192 

 Furze, li. 251 



Galapagos Archipelago, birds of, 



ii. 188 



, productions of, IL 197-202 



Galaxias, its wide range, ii. 181 

 Galeopithecus (flying lemur), i. 243 

 Game, increase of, checked by vennin, 



i. 109 



Gartner, on sterility of hybrids, ii, 



8-10, 17 



, on reciprocal crosses, ii. 21 



, on crossed maize and verbas- 



cum, ii. 43 

 , on comparison of hybrids and 



mongrels, ii. 46-48 

 Gaudry, Prof., on intermediate genera 



of fossil mammals in Attica, ii. 114- 



115 

 Geese, fertility of, when crossed, ii. 



15-16 



, upland, i. 248 



Geikie, Mr., on subaerial denudation, 



ii. 59 

 Grenealogy, important in classification, 



ii. 221 

 Generations, alternate, ii. 249 

 Geoff roy St.-Hilaire, on balanoement, 



i. 207 



, on homologous organs, ii. 242 



— — , Isidore, on variability of re- 

 peated parts, i. 209 

 — — , on correlation, in monstrosities, 



i. 37 



, on correlated variation, i. 204 



, on variable parts being often 



monstrous, i. 216 

 Geographical distribution, ii. 137 

 Gfeography, ancient, ii. 313 

 Geology, future progress of, ii. 312 

 , imperfection of the record, ii. 



313 

 Gervais, Prof., on Typotherium, ii. 



115 

 Giraffe, tail of, i. 271 



, structure of, i. 302 



Glacial period, ii. 159 



, affecting the North and South, 



ii. 167 

 Glands, mammary, i. 322 

 Gmehn, on distribution, it 169 

 Godwin-Austen, Mr., on the Malay 



Archipelago, ii. 80 



