Burns — Deposition and Incubation 277 



conspicuously or highly-colored than the other, the more 

 plainly-garbed sex frequently assumes all the duties of incu- 

 bation and not infrequently, of the young, also. 



Double monogamy occurs in many instances in every group 

 producing prsecocial young, but it is probably more common 

 in the Altrices ; double monogamy, however, as generally de- 

 fined, is not characteristic of the highest type, since of the 

 Turdidcc and Corvidce (except the subfamily Corviiicc) the two 

 Passerine families most in dispute for first rank ; the male does 

 not appear to render any assistance in incubation. 



According to present information, both sexes take regular 

 turns at incubating in at least some species of the Podicipidce, 

 Gaviida:, Atcidce, Laridce (not mcXuding Anous stoUdits, Noddy) , 

 Diomedeidce, Procellariidce, Phcethontidcs, Pelecanidcc, Aiueri- 

 ncB, Cygnince, Phccnicopteridce, Ihididcs, Ardeidce, some of the 

 Scalopacidcc, (Philohela minor Woodcock, Galtingo delicata 

 Wilson's Snipe, Pelidna alpina sakhalina, Red-backed Sand- 

 piper), Charadriidce (Osy\echus vociferous Killdeer), the ge- 

 nus Colinus only of the Gallinaceous birds, Colmnbidce, Buteo- 

 nidco, (except Aquila chrysaetos Golden Eagle), Stringes (ex- 

 cept the genus Otns), the genus Coccysiis, Alcedinidce, Pi- 

 cidce, CaprimidgidcB, and of the Passerines; Corvince, Zantho- 

 cephalus santhocephalus Yellow-headed Blackbird, Stnrnella 

 magna Meadowlark, the genus Quiscalus, most of the Frin- 

 gillidce (the most notable 'exceptions being of genera, includ- 

 ing nearly all of the most brilliant and conspicuously plum- 

 aged males, not including Zamelodia ludivicana Rose-breasted 

 Grosbeak), Hirundinidce (not including Progne subis Pu-rple 

 Martin)-, Bomby cilia cedrorum Cedar Waxwing, Protonotaria 

 citrea Prothonotary Warbler, Dendroica ccstiva custiva Yellow 

 Warrbler, D. pensylvania Chestnut-sided Warbler, Setopaga 

 ruticilla Redstart, Vireonidce (not including V. Philadelphia 

 and L. solitarius solitarius), Anthus pratensis Meadow Pipit, 

 the genera Toxostoma, Troglodytes, and Sitta canadensis Red- 

 breasted Nuthatch. 



Incubation is performed solely by the female in Anous sto- 

 lidus Noddy, the Anatidoe (except Anserinoe and Cygn-ince) 



