But she puts into them the soul of the body, which forms them that is the soul of the mother which first constructs in the womb the form of the man and in due time awakens the soul that is to inhabit it.

I have found that, in the composition of the human body as compared with the bodies of animals, the organs of sense are duller and coarser. Thus, it is composed of less ingenious instruments, and of spaces less capacious for receiving the faculties of sense.

And this network of veins acts in man as in oranges, in which the peel becomes thicker and the pulp diminishes the more they become old. And if you say that as the blood becomes thicker it ceases to flow through the veins, this is not true, for the blood in the veins does not thicken because it continually dies and is renewed.

Because, if it were all-pervading and the same in every part, there would have been no need to make the instruments of the senses meet in one centre and in one single spot; on the contrary it would have sufficed that the eye should fulfil the function of its sensation on its surface only, and not transmit the image of the things seen, to the sense, by means of the optic nerves, so that the soul - for the reason given above - may perceive it in the surface of the eye.

The frog retains life for some hours when the head the heart and all the intestines have been taken away. And if you prick the said cord it instantly twitches and dies.

That cause which moves the water through its springs against the natural course of its gravity is like that which moves the humours in all the shapes of animated bodies.