478 REPORT OF NATIONAL MUSEUM, 1892. 



blotches, and a clouding with brown and gray (Aquila). Bendire re- 

 marks of the Harpy Eagle (Thrasaetus harpyia) that "I have been un- 

 able to And a correct description of the egg of this species," and he 

 supplies one from the specimens of that bird in the TJ. S. National 

 Museum, and observes " the eggs are white, with yellowish-brown dots 

 and washes, and about as long, though not quite as heavy, as a hen's 

 egg. Of these eggs the Harpy lays 4 or 5, but never hatches more 

 than 2, and, if the Indians can be believed, feeds the first two eaglets 

 that make their appearance with the contents of the remainiug eggs" 

 (p. 271). 



Coming next to the Psittact, I find that neither Cones nor Ridgway 

 give in their works the number of eggs laid by our Carolina Paroquet 

 (Gonurus caroUnensis); the former says "eggs whitish, 1.40 x 1.05, 

 elliptical in shape, rough in texture" (p. 496), and the latter, "eggs 

 1.39x1.07, ovate, short ovate, or rounded ovate, pure white" (p. 270). 

 Dr.Sharpe says simply "egg white" for his Order Psittaciformes (p. 83). 

 I am of the opinion that the fact is not exactly known, and the truth of 

 the matter is, we stand sadly in need of a knowledge of much in the 

 biology of this entire and large group of most interesting birds. 



Coccyges : The parasitic habits of the European Cuckoo (C. canorus) 

 are too well known to require comment here, and Coues observes that 

 "the American Cuckoos have been declared free of suspicion of such 

 domestic irregularities; but, though pretty well behaved, their record 

 is not quite clean: they do sometimes slip into the wrong nest. The 

 curious infelicity seems to be connected in some way with the inability 

 of the female to complete her clutch of eggs with the rapidity and regu- 

 larity usual among birds, and so incubate them in one batch. The 

 nests of our species of Coccygus commonly contain young by the time 

 the last egg of the lot is laid " (p. 471). Such habits, however, are de- 

 parted from by the genus Crotophaga, birds which build a large nest for 

 the use of a number of the species to lay in in common. In Geococeyx 

 and Coccygus, species that lay numerous eggs at irregular intervals, we 

 find often a fresh egg just laid and perhaps a nestling half as large as 

 the parent bird, with an intermediate gradation of eggs in various 

 stages of incubation and young grading up to the size of the one just 

 mentioned. 



Crotophaga ani may lay as many as 8 eggs, which according to Coues 

 are "greenish" and to Ridgway a "dull glaucous-blue," but they are 

 always more or less overlaid with a white substance chalky in nature, 

 that in the recently laid egg easily washes off. Our Ground Cuckoo 

 (Geococeyx) also lays white eggs or of a pale buff- white, and there may 

 be as many as a dozen deposited before the bird completes her irregu- 

 larly lain clutch. Opinions do not agree as to the number of eggs laid 

 by our common Yellow-billed Cuckoo (0. americanus), Dr. Coues stating 

 " eggs 4 to 8, pale greenish" (p. 476), and Ridgway, " eggs 2 to 4, dull 

 pale glaucous-green or glaucous-white" (p. 273). And the latter au- 

 thority says of the Black-billed Cuckoo (C\ erytliroplithalmus "eggs 2 



