WHETHER, as Theophrastus writes, because it is an animal by nature timorous; and therefore, being disturbed, it changes color with its spirit, as some men do, of whom it is said, an ill man ever changes color? But though this may serve as a reason for changing its color, it will not for the imitation of colors. For the polypus does so change its color, that it is of the color of every stone it comes nigh. Hence that of Pindar, Mind the color of the marine beast, and so converse cunningly in all cities; and that of Theognis: And they say, that such as are excellent at craftiness and juggling have this in their eye,—that they may the better cheat them they have to deal withal,—ever to imitate the polypus. Some think the polypus can use her skin as a garment, and can put it on or off at pleasure. But if fear occasions this change in the polypus, is not something else more properly the cause? Let us consider what Empedocles says, that effluvia proceed from all things whatever. For not only animals, plants, the earth and sea, but stones, and even brass and iron, do continually send out many effluvia. For all things corrupt and smell, because there runneth always something from them, and they wear continually; insomuch that it is thought that by these effluvia come all attractions and insultations, some supposing embraces, others blows, some impulses, others circuitions. But especially about the sea rocks, when they are wet and cool by the waves (as is most likely), constantly some small particles are washed off, which do not incorporate with other bodies, but either pass by the smaller passages, or pass through the larger. Now the flesh of the polypus, as one may judge by the eye, is hollow, full of pores, and capable of effluvia. When therefore she is afraid, as her spirit changes she changes herself, and by straitening and contracting her body, she encloses the neighboring effluvia. And, as a good token of this argument, the polypus cannot imitate the color of every thing he comes near, nor the chameleon of any thing that is white; but each of these creatures is assimilated only to those things to whose effluvia it has pores proportionable.