From the beginning of October to the middle of May these birds are constantly found on our northern coasts, and on the rivers and estuaries with which they abound. When on a long journey, they keep at a great height, moving rapidly in a direct course with outstretched wings. On these occasions they exceed the speed of most of their congeners. With their long outstretched necks and snow-white breasts, from their comparatively short wings, they present a curious and novel sight. When swimming they are extremely vigilant, and permit nothing to approach them. On the appearance of a boat they glide as it were out of sight under the water, without noise or flutter, and thence pursue their way with great rapidity, using wings as well as feet to propel themselves. THE PENGUINS (_Aptenodytes_) Belong exclusively to cold countries. They rarely quit the vicinity of land, yet only take to the shore in the breeding season, or when driven by squalls and storms from their favourite element. On shore they are compelled to sit erect. They carry the head very high and the neck stretched out, while their short winglets are advanced like two diminutive arms. When they sit perched in flocks on some lofty projecting rock they might be mistaken at a distance for a line of soldiers. [Illustration: Fig. 81.--Penguin (_Aptenodytes_).] At certain periods of the year the Penguins assemble on the beach as if they preconcertedly met for deliberation. These assemblies last for a day or two, and are conducted with an obvious degree of solemnity. When the meeting results in a decision, they proceed to work with great activity. Upon a ledge of rock, sufficiently level and of the necessary size, they trace a square with one of its sides parallel and overlooking the edge of the water, which is left open for the egress of the colony. Then with their beaks they proceed to collect all the stones in the neighbourhood, which they heap up outside the lines marked out, to serve them as a wall, to shelter them from the prevailing winds. During the night these openings are guarded by sentinels. They afterwards divide the enclosure into smaller squares, each large enough to receive a certain number of nests, with a passage between each square. No architect could arrange the plan in a more regular manner. What is most singular is that the Albatross, a bird essentially aërial, and adapted for flight, associates at this period with these half fish, half birds, the Penguins; so that the nest of an Albatross may be seen next the nest of a Penguin, and the whole colony, so differently constituted, appear to live on the best terms of intimacy. Each keeps to its own nest, and if by chance there is a complaint, it is that some Penguin (probably the king Penguin, for he is generally the greatest thief) has robbed the nest of his neighbour, the Albatross.