Dr Wallace, in his “Natural Selection,” speaking of birds in general, tells us that, if permitted to live, in the ordinary course of production “in fifteen years each pair of birds would have increased to more than two thousand millions. Whereas we have no reason to believe that the number of the birds of any country increases at all in fifteen or in one hundred and fifty years. On the average, all above one become food for hawks and kites, wild cats or weasels, or perish of cold and hunger as winter comes on.” Myriads of white whelks are now scattered over the Rock surface, and already patches of mussels and acorn barnacles have been cleared by their voracity. Their ova, which is to be met with in almost every nook and cranny, is left to take care of itself. A patch of this ova is situated in a position which a paidle-hen subsequently fancied for a nursery, and, scorning all rights of possession, plastered her ova indiscriminately over that of the whelks, with the result that they are now under the special care of the guardian “cock.” A stranded cuttlefish was an object of much interest one evening this month. What a queer-looking object it appeared, with its eight long tentacles squirming in all directions, its body a slobbery mass of animated mucilage. Although only a foot in diameter it required some force to detach it from the rock, as each of the tentacles is furnished with rows of suckers on its under side. By extending the tentacles in front, the animal was able to move along the Rock surface, not in a jerky fashion, as might be expected, but with a continuous gliding motion, clearly showing that each sucker acted independently of its neighbour. If taken hold of, one or other of the tentacles is immediately twisted round the hand with a tenacity that seems surprising considering the size of the animal, and one can then realise to some extent the stories occasionally heard of its giant relatives of the tropics. Irritated, it appears to have the properties of the chameleon, flushing through all the gradations of colour in quick succession, and latterly discharging a jet of fluid of inky blackness. This resource, however, was utterly useless in the present circumstances, but, on placing the animal in a shallow pool of water, its use was at once apparent, for on being touched it immediately rendered itself invisible by the inky fluid discharged. Frequent irritation, however, exhausted its stock of ink, and latterly only clear water was expelled. This expulsion, when effected on the Rock, was accompanied by an audible murmur. The narrow slits of eyes closely resemble those of a dog-fish, and the head, with the anterior tentacle elevated in the air, grotesquely reminds one of an elephant in the act of trumpeting. _MAY 1903._