and Breslau grew well until last winter when
they were killed. Three Breslau seedlings did not winterkill.

Rumanian Giant, the first tree I grafted, killed back somewhat, but is
recovering. This variety produces the largest nut I have seen and it
fills well.

Top-worked trees of other varieties that were not injured last winter
are Crath No. 5, Crath No. 12, SG No. 5, Crath No. 29, Graham and Crath
Special.

Seedlings in the nursery row that stood severe temperature are
Carpathian D, NWF Nos. 1 and 3, FB O and FB OO, Fort Custer, Hansen,
Jacobs and others.

MR. STOKE: Does the black walnut bloom at the same time that the Persian
walnut blooms?

DR. MCKAY: It bloomed near the end of the receptive period.

MR. STOKE: That first experiment of yours was trying to pollinize the
black walnut with the Persian, but the reciprocal cross may be quite
different, as Jones proved with the filberts.

DR. McKAY: That could be. We have no large amount of data on the
reciprocal cross. These cases where it is said that the black walnut
pollinates the Persian regularly and is producing good crops of nuts, I
would consider doubtful until I see the seedlings, their growth and
characteristics. Yesterday Mr. Bolten asked the question whether or not
some walnuts that have large nuts could possibly be tetraploid or
polyploid. A number of years ago I examined the chromosomes of one of
these large fruited varieties, and it had the same chromosome number as
the others, namely sixteen pairs or thirty two.

The whole question of chromosome number in nut varieties and species is
as follows. So far as we know, all of the species have a constant number
within the genus except the hickories where we have tetraploid species
and diploid species. All of the species of _Castanea_, as far as we
know, have the same chromosome number, and all of the varieties within
each species have the same number. In the Oaks, which are related to
chestnuts, we have an extremely large genus in which there is a great
constancy of number. The pines, and all other cone-bearing trees make up
another very large group in which chromosome numbers are constant.
Exactly the opposite situation is found in the related family of alders
and willows where the chromosome number is very variable.

PRESIDENT MacDANIELS: Unless there is some special question or comment
on this subject, we will go on to the next item.

MR. LEMKE: There was a panel discussion about four years ago,