1§87.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 303 



erroneous theory, for uot onlj' have we white birds with the ornamental 

 plumes showing them to be fully adult, but actual observations have 

 established the fact that the young birds belong to the white or colored 

 phases already in the nest. What makes the question so very trouble- 

 some is the fact that there are hardly two species in which the relation 

 between the two phases is exactly alike. In the Little Blue Heron 

 {Florida coerulea), from the eastern parts of North America and the 

 West Indies, the white phase is seldom if ever perfectly developed in 

 the adults, while intermediate specimens are quite numerous. The 

 Eeddish Egret {Dichromannssa rufescens), upon which Mr. Ridgway be- 

 stowed the generic appellation in allusion to the dichromatism of its 

 plumage, may also be regarded as strictly dimorph, for in Florida, 

 where this species breeds abundantly, both phases are said to have 

 been found in the same nest, attended by parents either both reddish, 

 both white, or one in each of these stages of plumage, other circum- 

 stances at the same time leading to the conclusion that the two i^hases 

 are not only uot specifically distinct, but that they have nothing to do 

 with either sex, age, or season. It is not quite so certain that Ardea 

 occidenfaUs is now only a white phase of A. wardi, for it is stated that 

 in Florida the former is confined mainly to the Atlantic coast while 

 the latter chiefly inhabits the Gulf side. I believe that the differentia- 

 tion between the colored and the white phase of the Reef Heron has 

 reached a degree further. Butler (B. of ISTew Zealand, 1873, p. 229) 

 asserts that the white form has never yet been met with iu Few Zea- 

 land,* and according t9 Seebohm (Ibis, 1884, p. 177), it is also said to 

 be absent in Southeastern Australia. Kor do pied examples occur in 

 these localities, and contrary to the rule iu Florida coeriilea, these in- 

 termediate birds appear to be comparatively rare iu the Reef Herons, 

 for it seems that all the specimens collected by Mr. Hume and his col- 

 lectors on the islands in the Bay of Bengal (forty-one specimens) belonged 

 either to the normal dark form or to the pure white phase, and the same 

 was the case with the large collection of these birds by Mr. Titian Peale 

 (U. S. Exploring Expedition) from the Polynesian Islands. Among the 

 fifteen specimens enumerated by Schlegel {I. c.) as contained in the Lei- 

 den Museum only one appears to bo pied (No. 4). Von Pelzeln (Novara 

 Reise, Zool., I, Vogel, 1»69, pp. 118-123) examined thirteen specimens, 

 only two being pied. Dr. Finsch (Jour. f. Orn., 1870, pp. 136-139) does 

 not give data sufificiently explicit to enable us to state the proportion be- 

 tween the uniformly colored specimens aud the pied ones, but the latter 

 seemto be in a decided minority. I am therefore inclined to accept Mr. 

 Seebohm's theory {I. c.) that these pied individuals are hybrids between 

 the two forms, the more so since Dr. Finsch {totn. cit., p. 137) informs 

 us that he received from Viti-Levu a pair collected by Dr. Graffe, of 

 which the male was slate-colored, the female pure white, and both were 



* I may meution, however, that Schlegel enumerates a white bird in the Leyden 

 Museum as from New Zealand (Mus. P. Bas, Ardeaj, 1863, p. 27, No. 15.) 



