Книга только для ознакомления
. Examples of such
division are furnished by the hares of certain regions, which have the
appearance of having two livers, and by the cartilaginous and some
other fishes.
It is the position of the liver on the right side of the body that
is the main cause for the formation of the spleen; the existence of
which thus becomes to a certain extent a matter of necessity in all
animals, though not of very stringent necessity.
The reason, then, why the viscera are bilateral is, as we have said,
that there are two sides to the body, a right and a left. For each
of these sides aims at similarity with the other, and so likewise do
their several viscera; and as the sides, though dual, are knit
together into unity, so also do the viscera tend to be bilateral and
yet one by unity of constitution.
Those viscera which lie below the diaphragm exist one and all on
account of the blood-vessels; serving as a bond, by which these
vessels, while floating freely, are yet held in connexion with the
body. For the vessels give off branches which run to the body
through the outstretched structures, like so many anchorlines thrown
out from a ship. The great vessel sends such branches to the liver and
the spleen; and these viscera-the liver and spleen on either side with
the kidneys behind-attach the great vessel to the body with the
firmness of nails. The aorta sends similar branches to each kidney,
but none to the liver or spleen
|
