flat rocks, or reeds and herbage in swamps, is often a large fabric of sticks without lining or with a slight bedding of grass, leaves, and the like, but may be a mere mass of rushes and flags; the tree-building forms at times resorting to the ground and _vice versâ_. Bitterns generally crush down the aquatic vegetation and add softer materials on this substructure, depositing four or five olive-drab eggs; _Ardetta_ in some cases does the same, but the eggs are bluish- or greenish-white; whereas those of the Herons proper are of a greenish- or whitish-blue colour of varying depth, and exceptionally amount to six or seven. _Butorides_ not uncommonly lays only two. If the first set is removed a second is often produced after a short interval; but the young remain long in the nest. Incubation lasts from sixteen to thirty days. Herons were of old protected by law, as affording an excellent quarry for Falcons, while the flesh was highly esteemed; when wounded, however, they must be carefully approached, as they use the bill with deadly effect, and aim at the captor's eye. In India they are used as decoy-birds with the eyes sewn up. The following will sufficiently shew the coloration; the largest species is _Ardea goliath_; _Ardetta_ furnishes the smallest forms. _Botaurus stellaris_, the Bittern, which bred so lately as 1868 in Norfolk, and occurs throughout the warmer parts of the Palaearctic and the whole of the Ethiopian Region, is buff, with black bars above and streaks below, black crown, nape, and stripes down the side of the neck, and chestnut bands on the primaries. _B. lentiginosus_, distinguished by the nearly uniform brown primaries, is rarely found in Britain, but inhabits North America, probably meeting about Nicaragua with _B. pinnatus_ of tropical South America, which lacks the neck-stripes; while _B. poeciloptilus_ of the Australian Region has much of the back brown. The neck-feathers in these birds form an elongated ruff. _Ardetta minuta_ of Central and Southern Europe, Western Asia, and the northern half of Africa, formerly known to have bred in England, is greenish-black, with buff neck, wing-coverts, and under surface, the latter slightly streaked with dusky. These streaks are more decided in other species, which are often greyer, browner, or more ruddy above; _A. cinnamomea_ of the Indian Region is almost entirely rufous, while all have a slight head-tuft. A fuller crest marks _Zebrilus pumilus_ of northern South America, wherein {90}the upper parts are black with fulvous undulations, and the lower parts correspondingly mottled. The "Tiger-Bitterns" (_Tigrisoma_) extend from Central America to North Argentina, the four or five forms varying chiefly in the amount of naked skin on the throat. _T. brasiliense_ is blackish with rusty vermiculations above, and reddish-grey below, the head being mainly chestnut, and the tips of the remiges and spots on the breast white.