aether, whether cold or dense — the air they call cold aether, and the sea and moisture dense aether — and this ray descends even to the depths and for this reason quickens all things. All things live which partake of heat — this is why plants are living things — but all have not soul, which is a detached part of aether, partly the hot and partly the cold, for it partakes of cold aether too. Soul is distinct from life ; it is immortal, since that from which it is detached is immortal. Living creatures are reproduced from one another by germination ; there is no such thing as spontaneous generation from earth. The germ is a clot of brain containing hot vapour within it : and this, when brought to the womb, throws out, from the brain, ichor, fluid and blood, whence are formed flesh, sinews, bones, hairs, and the whole of the body, while soul and sense come from the vapour within. First congealing in about forty days, it receives form and, according to the ratios of " harmony," in seven, nine, or at the most ten, months, the mature child is brought forth. It has in it all the relations constituting life, and these, forming a continuous series, keep it together according to the ratios of harmony, each appearing at regulated intervals. Sense generally, and sight in particular, is a certain unusually hot vapour. This is why it is said to see through air and water, because the hot aether is resisted by the cold ; for, if the vapour in the eyes had been cold, it would have been dissipated on meeting the air, its like. As it is. in certain [lines] he calls the eyes the portals of