tructure of stock and
scion. If you have a good, smooth union, the two grow equally. Where you
have overgrowth of scion, you usually have a starved root, because the
food which is to be returned elaborated is checked at the point of
union, the root is starved, and you have a short lived tree, because
your root system, which ought to receive its share of the distributed
food, is underfed, finally weakens, and the whole structure fails.

Professor Lake: You may have mechanical union, but you can't have the
after fusion in which you are going to have proper function of stock and
scion.

Professor Craig: Each cell functions after its own kind. It is a
question of passage or transmission of food through that carrier, after
the union is effected. If the character of the two types differs very
much, the transmission of food is checked and is difficult.

President Morris: There is another mechanical point I'd like to ask
about. When the two types of cells differ, will the difference in degree
of capillarity regulate the amount of pabulum distributed, or does it
depend upon negative and positive pressure?

Professor Craig: That is a very difficult question, because it isn't
settled at the present time what credit we should give to capillarity
and what to root pressure in sap circulation.

Mr. Reed: There is another question I would like to ask Professor Craig.
Supposing you have a mechanical union perfected, what is the difference
in the food that different species of the same genus transmit? Has that
been worked out?

Professor Craig: I don't think so. Of course, there is a difference in
the food. That is proven, because there is a difference in the quality
of the food. The tree machine, the tree factory speaking individually,
evidently makes different products, and that is shown by the different
quality of nuts. That is all we know about it.

Professor Lake: That part below the scion still continues to be normal
hickory, and that part above, pecan, so really it is not a matter of
distribution of water supply by gravity or other pressure, but rather a
distribution of the proper amount of elaborated food; and that is
transmitted through the cell itself, not the cell walls. Because this
top makes a food that is different from the normal requirements, or
because the latent character of those cells below does not respond to
the food supply as actively as the part above, is the whole question, it
seems to me. If the cells be