HERON (Fr. _heron_; Ital. _aghirone_, _airone_; Lat. _ardea_; Gr. [Greek: erodios]: A.-S. _hragra_; Icelandic, _hegre_; Swed. _hager_; Dan. _heire_; Ger. _Heiger_, _Reiher_, _Heergans_; Dutch, _reiger_), a long-necked, long-winged and long-legged bird, the typical representative of the group _Ardeidae_. It is difficult or even impossible to estimate with any accuracy the number of species of _Ardeidae_ which exist. Professor Hermann Schlegel in 1863 enumerated 61, besides 5 of what he terms "conspecies," as contained in the collection at Leyden (_Mus. des Pays-Bas_, Ardeae, 64 pp.),--on the other hand, G. R. Gray in 1871 (_Handlist_, &c. iii. 26-34) admitted above 90, while Dr Anton Reichenow (_Journ. fur Ornithologie_, 1877, pp. 232-275) recognizes 67 as known, besides 15 "subspecies" and 3 varieties, arranging them in 3 genera, _Nycticorax_, _Botaurus_ and _Ardea_, with 17 sub-genera. But it is difficult to separate the family, with any satisfactory result, into genera, if structural characters have to be found for these groups, for in many cases they run almost insensibly into each other--though in common language it is easy to speak of herons, egrets, bitterns, night-herons and boatbills. With the exception of the last, Professor Schlegel retains all in the genus _Ardea_, dividing it into _eight_ sections, the names of which may perhaps be Englished--great herons, small herons, egrets, semi-egrets, rail-like herons, little bitterns, bitterns and night-herons. [Illustration: FIG. 1.--Heron.]