168 GRALL^E. 



word having some resemblance to the husky and croaking 

 sound with which it makes the swamps dismal during the 

 night. They nestle in large assemblages like rooks ; and 

 though they are easily thrown into momentary alarm, they 

 do not readily quit their breeding-places, unless the trees in 

 which they nestle are cut down. Their size (and probably 

 that is the case with many other birds, and may Jiave led w 

 confusion of species) appears to vary with the abundance and 

 productiveness of their pastures, as they are larger in the 

 extensive swamps of America than in Europe, where the soil, 

 generally speaking, is less humid, and the swamps covered 

 with less luxuriant vegetation. In the mature bird, the 

 head, back of the neck, scapulars, and upper part of the back, 

 are black, with blue and green reflections ; the sides of the 

 neck, the wings, the lower part of the back, and the tail, 

 are fine whitish grey ; and the rest of the under part is pure 

 white. To the hinder part of the head there is attached a 

 very elegant crest, which the birds can erect when excited. 

 That crest is pure white, eight or nine inches in length, and 

 consists of three feathers, which sheathe each other like 

 tubes, so that the whole appears as if it were one conical 

 feather, tapering gradually to a point. The young are with- 

 out the crest, and have those parts brown which in the 

 mature birds are black with glosses ; and, indeed, more or 

 less of brown over the whole of the upper part, and partially 

 also on the under, where it is mixed with yellowish white. 

 The plumage varies gradually from the yellowish brown of 

 the young to the richer tints of the old birds, so that they 

 are apt to be mistaken. As British birds, they are exceed- 

 ingly rare : one individual has been met with in the upper 

 part of the valley of the Thames, and another on the banks 

 of the Tweed : but whether these straggled from the conti- 

 nent or from America, .is not known.* 



* Bonaparte distinguishes between the European night-heron (Ni/cti- 

 corax Gardeni) and the American night-heron (Nycticorax americanus, 



