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ed to one another, in his pea plants. In the first generation, raised from his crossbreds, or, as he calls them, hybrids, there were seventy-five per cent dominants and twenty-five per cent recessives. When these plants were again self-fertilized and the offspring of each plant separately sown, a new surprise awaited the observer. The progeny of the recessives remained pure recessive; and in any number of subsequent generations never produced the dominant type again, that is, never reverted to the original parent, whose qualities had failed to appear in the second generation. When the seeds obtained by self-fertilizing the plants with the dominant characteristics were sown, it was found by the test of progeny that the dominants were not all of like nature, but consisted of two classes--first, some which gave rise to pure dominants; and secondly, others which gave a mixed offspring, composed partly of recessives, partly of dominants. Once more, however, the ratio of heredity asserted itself and it was found that the average numerical proportions were constant--those with pure dominant {212} offspring being to those with mixed offspring as one to two. Hence, it was seen that the seventy-five per cent of dominants are not really of identical constitution, but consist of twenty-five per cent which are pure dominants and fifty per cent which are really crossbreds, though like most of the crossbreds raised by crossing the two original varieties, they exhibit the dominant character only. These fifty crossbreds have mixed offspring; these offspring again in their numerical proportion follow the same law, namely, three dominants to one recessive. The recessives are pure like those of the last generation, but the dominants can, by further self-fertilization and cultivation of the seeds produced, be again shown to be made up of pure dominant and crossbreds in the same proportion of one dominant to two crossbreds. The process of breaking up into the parent forms is thus continued in each successive generation, the same numerical laws being followed so far as observation has gone. As Mendel's observations have now been confirmed by workers in many parts of the world, investigating many different kinds of plants, it would seem that this law which he discovered has a basis in the nature of things and is to furnish the foundation for a new and scientific theory of heredity, while at the same time affording scope for the collectio
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