قراءة كتاب Northern Nut Growers Association, Report of the Proceedings at the Third Annual Meeting Lancaster, Pennsylvania, December 18 and 19, 1912

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Northern Nut Growers Association, Report of the Proceedings at the Third Annual Meeting
Lancaster, Pennsylvania, December 18 and 19, 1912

Northern Nut Growers Association, Report of the Proceedings at the Third Annual Meeting Lancaster, Pennsylvania, December 18 and 19, 1912

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دار النشر: Project Gutenberg
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were in doubt whether they were hand pollinated hybrids or had been pollinated before we got the blossoms covered. Many of them evidenced a great number of distortions, and one of them I remember particularly whose shell was so thin it was just like a piece of brown paper; and there were several peculiarities that were quite noticeable in those hand pollinated nuts.

The Chairman: That is a very interesting point. When we come to consider deformities of nuts we shall find very many cases due to the character of the pollinization. I crossed the Persian walnut with the shagbark hickory and had nuts that year of just the sort of which Mr. Hunt speaks, with shells as thin as paper. One could crush them with the very slightest pressure of the finger. The shells were not well developed. Unfortunately the mice happened to get at all of those nuts. I don't know if they were fertile or not. The kernels were only about half developed. I should look for deformity in these nuts rather than a taking on of the type of one parent over the other, the idea being based on theoretical biological considerations. We had last year a photograph of a tree in California which apparently was a cross, a very odd cross—does any one remember about that California tree?

Mr. Wilcox: It was a cross between Juglans Californica and the live oak.

The Chairman: Both the foliage and the nuts were very remarkable and pertained to characters of these two trees. Such a cross to my mind would be wholly unexplainable excepting on the ground recently brought out by Loeb and his followers in crossing the lower forms of animal life and finding that the cell membrane of the egg, if destroyed, will allow of very wide fertilization subsequently with other species. It occurs to me now—I had no explanation last year, but it occurs to me now, knowing of Loeb's experiments—that it is possible that one of the parents, the parent California oak tree carrying the female flowers, might have had its sex cells subjected to some peculiar influence like acid, sulphurous acid, for instance, from some nearby chimney. Sulphurous acid perhaps from someone merely lighting a match to light a cigar under the tree; he might have so sensitized a few female flowers, may have so injured the cell membrane of a few female germ cells that cross pollinization then took place from a walnut tree. It is only on some such ground as the findings of Loeb that we can explain such a very unusual hybridization as that, which appeared to me a valid one, of a cross between an oak and a walnut.

(Secretary Deming then called attention to hybrids in the various exhibits.)

Professor Smith: I should like to ask why, if this free hybridization takes place in nature among the hickories, you do not have a perfect complex of trees showing all possible variations in the forest.

The Chairman: In answer to Professor Smith's question I will start from his premises and remark that we do have such complexities. The hickories are so crossed at the present time, like our apples, that even crossing the pollen of various hickory trees of any one species does not promise interesting results unless we cross an enormous number. They are already so widely crossed that it is very difficult sometimes to determine if a certain tree is shagbark or pignut or shellbark or mockernut. For the most part the various species and varieties of hickories retain their identity because their own pollen is handiest, and different species do not all flower at the same time. Their own pollen from the male flowers is apt to fall at the time when their own female flowers are ripe and under these circumstances the chances are very much in favor of the tree pollinizing its female flowers with its own pollen. On the other hand, there is hardly one chance in many hundred thousand for any crossed nut to grow, for the reason that most nuts are destroyed by mice, squirrels, rats and boys. If you have a hickory nut tree growing in a lot, and which has produced a bushel of hickory nuts year after year, do you know of one single nut from that tree which has grown? In this plan of Nature, this plan of enormous waste of Nature in order to get one seed to grow, the chance for a hybridized hickory nut to grow under normal conditions, is so small that we should have relatively few crossed trees growing wild in Nature, though we do find quite a good many of them.

Professor Smith: If I am not taking up too much time, I would like to put some more questions to you.

The Chairman: That's what we are here for.

Professor Smith: Have you ever tried the plan of serving collations to squirrels? Why wouldn't it pay to give them portions of wheat and corn? Second, what percentage of the oak pollen kept in cold storage a month was alive? Third, what is the range of time that the hybridizer has to make the pollinization? Must we go on the dot or have we two days or four days or a week, in the case of hickories and walnuts?

The Chairman: I think possibly as these are three direct questions, I might answer them now. No, I think it would be better to have all questions bearing on this subject brought out and then I will answer all together. So if you will kindly ask all the questions, I will then endeavor to answer them.

Mr. Corsan: The squirrels bothered me last year. I've got forty acres of land for experimental purposes only and I started planting and the little beggars would dig down exactly where I planted the nuts, so I went into town and got a rat trap with a double section so I could catch them alive; and I caught so many by feeding them cheap pignuts, the sweet pignuts from Michigan, that I brought them in and my boys sold them for twenty-five cents apiece. Since then we have never been bothered with red squirrels. For the white footed mice I laid down large doors over some hay or long grass and they gathered underneath and then I lifted the doors up every day and with a stick I smashed hundreds of them. I have posted a notice to leave the skunk and mink alone; I don't want anybody on the place shooting them.

The Chairman: I will first answer Professor Smith's questions. This matter of serving collations for squirrels had best be done as collations are served at political meetings—with a trap attached. You don't know how many squirrels there are in the vicinity or how many white footed mice. You will be surprised at the numbers of the little rascals, and not only that, but the field mice, the common field mouse and pine mouse run in mole holes under the ground and can smell a nut a long way off. They are extremely destructive. What percentage of pollen grains of the white oak were alive? I do not know. Enough to fertilize a number of flowers. The sooner pollen is used the better. I cannot answer the question exactly because I did not make an experiment in the laboratory to know what part of the pollen was viable. I put on a good deal of it and there were at least some viable grains in the lot. That, however, is a matter which can be subjected to exact laboratory tests without any difficulty. I am so busy with so many things that I can only follow the plan of the guinea hen that lays forty eggs and sits in the middle of the nest and hatches out all she can. Now the range of time for pollinizing is a thing of very great importance and we have to learn about it. We must all furnish notes on this question. With some species I presume the duration of life of pollen, even under the best conditions, might be only a few days. Under other conditions it may be several weeks; but we have to remember that, in dealing with pollen, we are dealing with a living, breathing organism.

The Secretary: I believe the experiment has been carried to completion of fruiting a thousand trees from nuts grown on one pecan tree without two of the resulting nuts being like one another or like the parent nut. Is that true, Mr. Reed.

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