306 CHAPTERS ON THE NATURAL HISTORY 



doubled beauty, nor do his charms cease here, for as a songster 

 lie commands a talenl and a power peculiarly his own. None of 

 our avian performers possess the wonderful ringing, bell-like 

 notes of the Wood Thrush. Usually he is silent in the middle part 

 of tlie day. unless, perchance, it be a gray day, when — as is in- 

 variably I lie rule for him morning and evening — he will mount 

 to the top of some tree taller than the surrounding ones in some 

 dense piece of limber land, and from there lie will pour out, in 

 mellow, reverberating cadence, his several flute-like notes, with 

 a peculiar rippling harmony thai once heard can never be forgot- 

 ten. They are soon answered hither and far in the forest by rival 

 performers of the same species, and that with an apparently in- 

 creasing ardor and ecstasy, until one can almost believe these 

 feathered challengers are vicing wilh each oilier in their efforts 

 to produce I he sweetest and softest responses. They close only 

 as night draws on. first one bird and then another rendering its 

 clear, quavering finale, as a parting good-night, to tranquillize 

 the mind of I he weary rambler as he trudges homeward, after a 

 long and pleasurable day speul far afield. 



He it said here that ne.xt to t he fact that all birds possess feath- 

 ers, is the common character that every representative of this 

 group of vertebrates lay eggs, from the hatching of which their 

 young are brought forth. No such corresponding rules can lie 

 drawn in the case of mammals, however, for there are mammals 

 in existence that do not possess hair, as some of the whales for 

 example; nor do they all bring forth their young alive, as the 

 Monotremes, of Australia and the East Indies, lay eggs from 

 which the young are produced. 



Now. all hough all birds lay eggs, the places where those eggs 

 are deposited for hatching are nearly as various as the species of 

 birds themselves, surely far more so than the number of families 

 of the class. Not confining ourselves to any particular country, 

 we may have in the first place plenty of species of birds that 

 make no nesls al all to contain their eggs. They simply lay 

 them upon the bare rocks, or the ground. Most all those marine 

 forms known as auks have I his habil well marked, as do a great 

 many oilier species among the lower groups, as for example the 

 albatrosses. Bennett, in describing the King penguins of Mac- 

 quarrie island, in the south Pacific ocean, said: "The females 

 hatch (he eggs by keeping them close between the thighs, and if 



approached during the lii I' incubation, move away, carrying 



their cgtrs with I hem." 



