492 REPORT OF NATIONAL MUSEUM. 1892. 



Good examples of this are seen among our wren. v Troglodytidce). These 

 birds all lay in places where their eggs are not exposed to view, yet 

 some of them lay pure white eggs, and others those which are very 

 dark and densely spotted. It is seen again in Harporhynchus, where 

 H. rufus lays whitish eggs speckled with brown, and its first cousin in 

 the same genus, //. crissalis, two emerald-green and unspotted eggs. 

 Such apparent anomalies would appear almost to defy a correct solu- 

 tion. 



When we come to the Fringillidce it is even still more difficult to 

 account for the peculiarities of the colors assumed by the shells of their 

 eggs. Here we find species of the same genus, habits alike, nesting 

 alike, and the localities inhabited much alike, and yet laying very 

 different appearing eggs. For example, the Black-faced sage Sparrow 

 (A. bilineata), which lays whitish, unmarked eggs, ami the California 

 sage Sparrow (A. belli), which lays greenish-blue speckled eggs. 



Another interesting case is one that I have alluded to in my table 

 on the oology of the Passeres given above, and we find it among the 

 "Grosbeaks." Those birds, so called, usually all lay handsomely 

 marked eggs; but the Blue Grosbeak (O. ccerulea) lays a plain egg 

 quite like the oik 4 laid by the Indigo Bird of the genus Passerina (P. 

 eyanea), only larger. Now, the Blue Grosbeak in plumage and other 

 characters is strikingly like an Indigo Bird, and 1 believe that this is 

 an instance pointing to the affinity of the two forms: indeed, I further 

 believe that the Blue Grosbeak is more nearly related to our Indigo 

 Bird than are some of the other species they have placed in the same 

 genus with the latter, as, for instance. Passerina ciris and Passerina 

 versicolor, birds that lay pearly-white eggs speckled with brown of 

 two shades. When 1 say this 1 am also aware that the eggs of the 

 Indigo are occasionally speckled. In the popular mind the name 

 "Grosbeak 1 ' has given the impression that a number of birds in this 

 country so designated are much of the "same kind of species," whereas 

 in reality the affinity in several instances is not so close as is generally 

 supposed. For example, Guiraca is structurally much more nearly 

 related to Passerina cyanea than it is to Habia, and still nearer than it 

 is t<> either Gardinalis or Pyrrhuloxia. 



Finally, among our Tcteridce we find beautiful examples of that class 

 of cases (fifth law) where the male bird is of very handsome plumage; 

 the female (the incubator) more or less somber in that respect; and 

 where the eggs, more or less exposed to view (oftener less or partially 

 concealed), are very remarkably and exquisitely decorated. 



My examinations and studies of the oology of North American birds 

 have clearly shown me that we should strive more and more towards 

 correct and exact observation in such matters. It is especially needed 

 to have before the oologist abundance of material, and they should 

 seek to employ a common nomenclature in the description of colors, 

 tints, hues, and shades. This is also applicable to the descriptions of 



