the snout; while the cavity called _case_ is situated beneath and to the right of the spouting canal, and corresponds to nearly the entire length of that tube. It is filled with a very delicate web of cellular tissue, containing in large cells a limpid and oily fluid, which is liberated by the slightest force. The quantity, chiefly spermaceti, contained in this singular receptacle, is often very considerable, nearly 500 gallons having been obtained from the case of one whale. So vast an accumulation of fat has obviously been intended to insure a correct position in swimming, to facilitate the elevation of the spiracle above the surface of the sea, and to counteract the weight of the bony and other ponderous textures of the head; objects which in the Greenland whale are sufficiently attained by a similar accumulation of fat in the lips and tongue, and by the more elevated situation of the spout-hole. While the large whalebone whales generally roam about in solitary couples, the cachalot forms large societies. _Schools_, consisting of from twenty to fifty individuals, are composed of females attended by their young, and associated with at least one adult male of the largest size, who generally takes a defensive position in the rear when the school is flying from danger. _Pods_ are smaller congregations of young or half-grown males, which have been driven from the maternal schools. Two or more schools occasionally coalesce to a "_body of whales_," so that Bennett[L] sometimes saw the ocean for several miles around the ship swarming with sperm leviathans, and strewn with a constant succession of spouts. These large assemblies sometimes proceed at a rapid pace in one determinate direction, and are then soon lost sight of; at other times they bask and sleep upon the surface, spouting leisurely, and exhibiting every indication of being _at home_, or on their feeding ground. Like most gregarious animals, the cachalots are naturally timid. A shoal of dolphins leaping in their vicinity is sufficient to put a whole school to flight: yet occasionally fighting individuals are met with; particularly among those morose solitary animals that most likely from their intolerable character have been turned out of the society of their kind. The central deserts of ocean, or the neighbourhood of the steepest coasts, are the chief resort of the cachalot; and so great is the difference of his _habitat_ from that of the smooth-backed whales, that during the whole time Bennett was cruising in quest of cachalots, he in no single instance saw an example of the true whale. The cachalot is more especially found on the _line-currents_, which extend from the equator to about the seventh degree of north and south latitudes, yet it has been noticed in the Mediterranean, and one individual, a stray sheep indeed, has even been captured in the Thames. [Footnote L: Narrative of a Whaling Voyage round the Globe.]