as through a garden, that it might be watered as from a running
stream. In the first place, they cut two hidden channels or veins down
the back where the skin and the flesh join, which answered severally
to the right and left side of the body. These they let down along the
backbone, so as to have the marrow of generation between them, where it
was most likely to flourish, and in order that the stream coming down
from above might flow freely to the other parts, and equalize the
irrigation. In the next place, they divided the veins about the head,
and interlacing them, they sent them in opposite directions; those
coming from the right side they sent to the left of the body, and those
from the left they diverted towards the right, so that they and the skin
might together form a bond which should fasten the head to the body,
since the crown of the head was not encircled by sinews; and also in
order that the sensations from both sides might be distributed over the
whole body. And next, they ordered the water-courses of the body in a
manner which I will describe, and which will be more easily understood
if we begin by admitting that all things which have lesser parts retain
the greater, but the greater cannot retain the lesser. Now of all
natures fire has the smallest parts, and therefore penetrates through
earth and water and air and their compounds, nor can anything hold it.
And a similar principle applies to the human belly; for when meats and
drinks enter it, it holds them, but it cannot hold air and fire, because
the particles of which they consist are smaller than its own structure.

These elements, therefore, God employed for the sake of distributing
moisture from the belly into the veins, weaving together a network
of fire and air like a weel, having at the entrance two lesser weels;
further he constructed one of these with two openings, and from the
lesser weels he extended cords reaching all round to the extremities of
the network. All the interior of the net he made of fire, but the lesser
weels and their cavity, of air. The network he took and spread over the
newly-formed animal in the following manner:--He let the lesser weels
pass into the mouth; there were two of them, and one he let down by the
air-pipes into the lungs, the other by the side of the air-pipes into
the belly. The former he divided into two branches, both of which he
made to meet at the channels of the nose, so that when the way through
the mouth