Page:Popular Science Monthly Volume 80.djvu/382

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378
THE POPULAR SCIENCE MONTHLY

it would he difficult to overestimate the importance of the results certain to be obtained within the next fifty years. It has even been found that Mendel's discovery lights up the way toward the improvement of the human race, and it may well be that many of us now living will see the day when Mendelian questions will enter the field of practical politics.

As experimental work progressed, it was found that many complications arose, so that it was often difficult to interpret the results. Without going into these matters in detail, we must note that frequently the first cross "DR" is not like either parent, that is to say, dominance is not complete. Indeed, experienced breeders say that they can

Red Sunflower.

nearly always tell an impure form from a pure individual, although at first sight they may look alike. Critics of Mendelism were at first inclined to think that the failure of strict "dominance" invalidated the theory, but this is by no means the case, as the elements separate out in the third generation, just as before. The only difference is that as one can tell the DD from the DR, in the third generation we have three visible types instead of two, in the proportions 1, 1, 2.

Now to return to the sunflower; the first thing we were anxious to know was, will the red be dominant? From analogy with other cases, we thought it would. Being impatient, we obtained permission from our friend Mr. Knudsen to grow a few plants during the winter of