Index 



249 



Focusing-cloth, adjustment of, in 

 tent, 60-6 1 



Food, of young Cedar-birds, 38, 92, 

 100 ; of the House Wren, 43 ; econ- 

 omy of, in Kingbird, 52, 183; of 

 Kingbird, 52, 183, 184, 209-210; 

 of young Robins, 74, 82, 210; of 

 Robin in summer and winter, 

 83-84; of Cedar-bird, 87, 102; 

 distribution of, to nestlings ex- 

 plained, 92; and its distribution 

 in Red-eyed Vireos, 108-110; 

 economy of, in Red-eyed Vireos, 

 109; of young Bluebirds, 120; of 

 young Catbirds, 127-128; of 

 young Night Hawk, 134; of young 

 Kingfishers, 140, 144; of Euro- 

 pean Blackbird, 181 ; economy of, 

 in Chestnut-sided Warbler, 193; 

 of birds under exceptional con- 

 ditions, 2 1 1 ; of young Flicker, 226 



Foster-children, treatment of, by 

 Kingbird, 51; treatment of, by 

 Chipping Sparrow, 222-223 



Fowl (Callus bankiva var. domes- 

 tica), production of eggs in, 13; 

 strength of incubating instinct 

 in, 27, 179; physiological zero- 

 point in development of, 170; 

 normal temperature in develop- 

 ment of, 170; eating its eggs, 

 170; turning its eggs, 171 



Fruits, fed to young by Cedar- 

 birds, 38, 100 ; fed to young, by 

 Robins, 83; eaten by Robin in 

 winter. 83; cultivated, eaten as 

 makeshift, 83-84; served to 

 young of Red-eyed Vireos, no; 

 served to young, of Catbird, 128 



Galapagos Islands, observations of 



Darwin on fauna of, 242, 243 

 Gaping, habit of, in birds, 180 

 Gluttony in Cedar-birds, 181-182 

 Goldfinch, American (Spinus tris- 

 tis) , lateness of breeding and food 

 of young of, 87; attracted by 

 Robin's alarm, 224 

 Goose, Canada (Branta canaden- 

 sis), tameability and breeding of, 



Grampus (Corydalus cornutus), as 



food of young Kingbirds, 186, 

 187 



Grasshoppers, treatment of, by 

 Wrens, 41, 74, 100, 118 



Groos, Karl, xviii 



Grosbeak, Pine (Pinicola enuclea- 

 tor), habits, and relative tame- 

 ness of, in winter and spring, 

 240; capture of male of, with 

 hat, 241; character of fear in, 

 242-243 



Gull, Great Herring (Larus argen- 

 tatus smithsonianus) , diffusion of 

 nest-building instinct in, 12; ap- 

 plication of method to the study 

 of, 34; nest-cleaning of, 55; 

 alarm calls of, 55; sleeping hab- 

 its of, 112; significance of grass- 

 pulling and wood-splitting habits 

 of, 163-165; repair of nests in, 

 164-165; turning of eggs by, 

 171; the eating of the allantois, 

 or respiratory sac, by, 173 



Gullet, automatic response of, in 

 young birds, 92, 182, 198, 199; 

 distensibility of, in the Cedar- 

 bird, 92, 100 ; effect of full, in 

 young, 181 



H 



Habit, definition and illustrations 

 of, 204-207; of sipping maple 

 sap in Cedar-bird, 101; manner 

 of approach to nest of Red-eyed 

 Vireo, 206; of walking backward 

 and sitting still in young King- 

 fishers, explained, 136; of eating 

 excreta, how acquired in a 

 hungry bird, 193; illustration of , 

 in nest-cleaning, 208; plasticity 

 of, in reference to food, 210, 211; 

 of fear of special obiects, 221, 

 227; inheritance of, 212; evolu- 

 tion of, 213 



Hawks, instinct of spreading over 

 prey in, 202; feeding on locusts, 

 2ii ; effect of, on chicks, 219 



Hunger, effect of, on nestlings, 198- 

 199 in relation to fear, 230-23 1 



Incubation, period of, in Kingbird, 

 49; in Robin, 72; in Cedar- bird, 



