CLASS V. _When the adults of both sexes have a distinct winter and summer plumage, whether or not the male differs from the female, the young resemble the adults of both sexes in their winter dress, or much more rarely in their summer dress, or they resemble the females alone; or the young may have an intermediate character; or again, they may differ greatly from the adults in both their seasonal plumages._—The cases in this class are singularly complex; nor is this surprising, as they depend on inheritance, limited in a greater or less degree in three different ways, namely by sex, age, and the season of the year. In some cases the individuals of the same species pass through at least five distinct states of plumage. With the species, in which the male differs from the female during the summer season alone, or, which is rarer, during both seasons,[269] the young generally resemble the females,—as with the so-called goldfinch of North America, and apparently with the splendid Maluri of Australia.[270] With the species, the sexes of which are alike during both the summer and winter, the young may resemble the adults, firstly, in their winter dress; secondly, which occurs much more rarely, in their summer dress; thirdly, they may be intermediate between these two states; and, fourthly, they may differ greatly from the adults at all seasons. We have an instance of the first of these four cases in one of the egrets of India (_Buphus coromandus_), in which the young and the adults of both sexes are white during the winter, the adults becoming golden-buff during the summer. With the Gaper (_Anastomus oscitans_) of India we have a similar case, but the colours are reversed; for the young and the adults of both sexes are grey and black during the winter, the adults becoming white during the summer.[271] As an instance of the second case, the young of the razor-bill (_Alca torda_, Linn.), in an early state of plumage, are coloured like the adults during the summer; and the young of the white-crowned sparrow of North America (_Fringilla leucophrys_), as soon as fledged, have elegant white stripes on their heads, which are lost by the young and the old during the winter.[272] With respect to the third case, namely, that of the young having an intermediate character between the summer and winter adult plumages, Yarrell[273] insists that this occurs with many waders. Lastly, in regard to the young differing greatly from both sexes in their adult summer and winter plumages, this occurs with some herons and egrets of North America and India,—the young alone being white.