Then I began: Agemachus himself helps us exceedingly towards this discovery; for nothing at the present seems more probable than that, together with the thunder, oftentimes generative waters fall, which take that quality from the heat mixed with them. For the piercing pure parts of the fire break away in lightning; but the grosser windy part, being wrapped up in cloud, changes it, taking away the coldness and heating the moisture, altering and being altered with it, affects it so that it is made fit to enter the pores of plants, and is easily assimilated to them. Besides, such rain gives those things which it waters a peculiar temperature and difference of juice. Thus dew makes the grass sweeter to the sheep, and the clouds from which a rainbow is reflected make those trees on which they fall fragrant. And our priests, distinguishing it by this, call the wood of those trees Iris-struck, fancying that Iris, or the rainbow, hath rested on them. Now it is probable that when these thunder and lightning showers with a great deal of warmth and spirit descend forcibly into the caverns of the earth, these are rolled around, and knobs and tumors are formed like those produced by heat and noxious humors in our bodies, which we call wens or kernels. For a mushroom is not like a plant, neither is it produced without rain; it hath no root nor sprouts, it depends on nothing, but is a being by itself, having its substance of the earth, a little changed and altered. If this discourse seems frivolous, I assure you that such are most of the effects of thunder and lightning which we see; and upon that account men think them to be immediately directed by Heaven, and not depending on natural causes.