Page:Popular Science Monthly Volume 82.djvu/46

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I wish to study the cryptogamic diseases of my wild wheat in order to try to discover if among them there are any peculiar to wheat in other regions and which here would attack other plants. We could then say this or that cryptogam was carried by cereals and would be found in the same situation in relation to wheat, as certain phanerogamic satellites such as Lolium temulentum, Githago segetum, etc., etc.

I am sending with this letter a small photograph showing our workmen sowing Triticum dicoccoides with a drill. I shall not conceal from you that I am very proud that when for the first time since prehistoric times man has again tried sowing the prototype of wheat, this work has fallen to Jews (escaped from the ignoble massacres of Russia), Jewish teams working on Jewish ground, the historic cradle of the race.

Yours sincerely,

2em

You perceive the wide field which this discovery has opened up. The utilization for new needs of new races of wheat to be segregated from this wild material, that is, from the polymorphic plant populations of the hills of Judea, the extension of the cultivation of cereals to arid regions or mountainous zones, where it has hitherto not been possible.

But there is more than that. We possess now, and Mr. Aaronsohn alludes to it in his letter, a second method of improving wheat by the method of selection, growing pure races from single seeds.

We can, by crossing, create new races and in this domain modern methods have a startling precision. They say that the man who suddenly had a new world revealed to him by the microscope lost his reason. To-day, placed in the presence of the facts brought to light by modern biological analysis, we can see in our minds an infinite line of discoveries which were not even suspected by the generations preceding us.

Here, in a few words, are the results already obtained:

They lead us to suppose the existence of essential representative particles within the germ cells of plants. These particles may be compared to the atoms which chemists suppose to exist in the inanimate world. These are the biological elements, the "organic corpuscles" as Buffon would have called them. We call them "gens." The body of the plant with its diverse characters is then only the exterior manifestation of these "determinants." We suppose, then, that each character manifested is determined by a "gen," a "determinant." To constitute an organism with its characters there must be an association of gens.

For the sake of similarity in studies on heredity plants belonging to the same systematic grouping, the same genus or the same species, are usually compared. Only the characters in which these two plants differ are taken into account. For example, a race $$X$$ will differ from