tongue like a rasp, having recurved spines or teeth) is continued the alimentary canal, œsophagus, crop, gizzard, stomach, and intestines; and within this so-called “empty pouch” are also the liver, and the organs of reproduction and respiration. The “tentacles,” or arms, cannot be “turned inside out like the fingers of a glove.” On making a section across one of them, it will be seen that it is composed of close muscles, the fibres of some of which run longitudinally, and others transversely. The arm, therefore, is more like the strong flexible lash of a stout hunting whip than the finger of a glove, and is solid, except that it has a perforation along the centre of its axis for the lodgment of its nerve and artery. [Illustration: Fig. 4. Tongue of the Octopus (_O. vulgaris_). Magnified 12 diameters.] The author accurately describes the action and movement of the octopus, and its utilisation of its eight arms when crawling at the bottom, or on ledges of rocks. The globose body is then turned upward, the mouth downward, and the arms sprawl along, and by grappling some fresh object drag the body after them. But he is mistaken concerning its mode of progression when swimming. After stating that in swimming, it, so to speak, sheaths and draws close together its arms, which is quite true, he continues:— “Figure to yourself a sleeve sewn up with a fist in it. This fist, _which is the head_, pushes through the water, and advances with an undulating movement.” That which M. Hugo supposes to be the head is the body of the animal. He appears to have received this impression from Pliny,[13] who writes:—“The head, which is directed obliquely when they swim, is, in the living animal, hard and distended like a balloon.” The cuttle-fishes, and the octopus amongst them, propel themselves rapidly _backward_, when swimming, by the forcible expulsion from the funnel, in sudden and frequent jets, of the water drawn in at the branchial, or gill openings. Thus the organs of respiration become those of locomotion as well, and the funnel has also another function, being the orifice from which the excreta are expelled. It has been asserted by various writers—and the statement has been repeated by many able naturalists—that the octopus swims by vigorous flappings of the expanded membrane which extends from the sheath of the mouth along the arms, and connects the bases of the latter like the web of a duck’s foot. It is true that this sometimes, though very rarely, takes place, but its proper and usual mode of progression is with the body in advance, the arms closely packed together, and directed backward horizontally in its wake, whilst the jets of water, pumped out at frequent intervals from the funnel, propel it at a considerable speed. I have had opportunities of watching the habits of at least a hundred individuals of this species, yet have only three or four times seen them progress, when swimming, by powerful