M. Darwin in his _Voyage round the World_, thus describes a Crab which lives upon Cocoa-nuts, and which he found on Keeling Island, in the South Seas: "It is very common on all parts of the dry land, and grows to a monstrous size; it has a front pair of legs, terminated by very strong and heavy pincers, and the least pair by others which are narrow and weak. It would at first be thought quite impossible for a crab to open a strong cocoa-nut covered with the husk; but M. Liesk assures me he has repeatedly seen the operation effected. The crab begins by tearing the husk, fibre by fibre, and always from that end under which the three eye-holes are situated; when this is completed, the crab commences hammering with its heavy claws on one of these eye-holes till an opening is made. Then, turning round its body, by the aid of its posterior and narrow pair of pincers, it extracts the white albuminous substance. I think this is as curious a case of instinct as ever I heard of, and likewise of adaptation in structure between two objects apparently so remote from each other in the scheme of nature, as a crab and a cocoa-nut." ------------------ DESCARTES' WOODEN DAUGHTER. When Descartes resided in Holland, he made with great labour and industry a female automaton, which gave some wicked wits occasion to report that he had an illegitimate daughter, named Franchine. The object of Descartes was, to demonstrate that beasts have no souls, and are but machines nicely composed, that move whenever another body strikes them and communicates to them a portion of its motions. Having carried this singular machine on board of a Dutch vessel, the captain, who sometimes heard it move, had the curiosity to open the box. Astonished to see a little human form uncommonly animated, yet when touched appearing to be nothing but wood--and being little versed in science, but very superstitious--he took the ingenious labour of the philosopher for a little devil, and terminated the experiment of Descartes, by throwing his "wooden daughter" into the sea. ------------------ ASTRONOMICAL SHOEMAKER. When Halley's comet was expected in 1835, a shoemaker of Leicester, named Joseph Mills, set about tracing the path of the heavenly visitor through the heavens. This he did by drawing its orbit upon his house floor, from which he made a diagram that more accurately represented the course of the comet than any that had been previously published. On being questioned how he had calculated the disturbing forces, so as to come so near the truth; he replied that he could not tell, further than he had performed it by the common rules of arithmetic. ------------------ DECLINE OF SCIENCE.