608 REPORT OF NATIONAL MUSEUM, 1893. 



DivEKSiTY IN Color of Eggs. 



There is an extraordinary diversity in the color, form, and disposi- 

 tion of nuirkiugs, etc., of the eggs of M. honariensis; and I doubt 

 whetUer any otlier species exists hiying eggs so varied. About half 

 the eggs one finds, or nearly half, are pure unspotted white, like the 

 eggs of birds that breed in dark holes. Others are sparsely sprinkled 

 with such exceedingly minute specks of pale pink or gray as to appear 

 quite spotless until closely examined. After the pure white, the most 

 common variety is an egg with a white ground, densely and uniformly 

 spotted or blotched with red. Another uot uncommon variety has a 

 very pale, tiesh-colored ground, uniformly marked with fine characters, 

 that look as if inscribed on the shell with a pen. A much rarer variety 

 has a pure white shell Avith a few large or variously sized chocolate 

 spots. Perhaps the rarest variety is an egg entirely of a fine deep red; 

 but between this lovely marbled egg and the white one with almost 

 imperceptible specks there are varieties without number, for there is 

 no such thing as characteristic markings in the eggs of this species, 

 although, as I have said before, the eggs of the same individual show 

 a family resemblance. 



Habits of the Young of M. Bonariensis. 



Small birds of all species, when first hatched, closely resemble each 

 other. After they are fledged the resemblance is less, but still com- 

 paratively great. Gray, interspersed with brown, is the color of most 

 of them, or at least of the uj^per exposed plumage. There is also a 

 great similarity in their cries of hunger and fear — shrill, querulous, 

 ])rolonged, and usually tremulous notes. It is not, then, to be won- 

 dered at that the foster parents of the young MoJothrus so readily 

 respond to its cries, understanding the various expressions denoting- 

 hunger, fear, pain, as well as when uttered by their own offspring. 

 But the young Molothrus never understands the language of its foster 

 jjarents as other young birds understand the language of their real 

 parents, rising to receive food when summoned, and concealing them- 

 selves or trying to escape when the warning note is given. How does 

 the young Molothrus learn to distinguish, even by sight, its foster 

 parent from any other bird approaching the nest? It generally mani- 

 fests no fear even at a large object. On thrusting my fingers into any 

 nest I find the young birds, if still blind or but recently hatched, will 

 hold up and open their mouths, expecting food; but in a very few days 

 they learn to distinguish between their^ parents and other objects 

 approaching them, and to show alarm even when not warned of danger. 

 Consider the different behavior of three species that seldom or never 

 warn their offspring of danger : The young of SynaUaxiH ,spi,ri, though in 

 a deep, domed nest, will throw itself to the ground, attempting thus to 

 make its escape; the young of Mimusjyatagonicus sits close and motion- 

 less, with closed eyes, mimicking death; the young of our common 



