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