It is very easy to count the number of both sorts of grains in the spike
of such a hybrid. In doing so we find, that the proportion is nearly the
same on all the spikes, and only slight variations would be found in
hundreds of them. One-fourth of the seeds are wrinkled and three-fourths
are always smooth. The number may vary in single instances and be a
little more or a little less than 25%, ranging, for [291] instance, from
20 to 27%, but as a rule, the average is found nearly equal to 25%.
The sugary kernels, when separated from the hybrid spikes and sown
separately, give rise to pure sugary race, in no degree inferior in
purity to the original variety. But the starchy kernels are of different
types, some of them being internally like the hybrids of the first
generation and others like the original parent. To decide between these
two possibilities, it is necessary to examine their progeny.
For the study of this third hybrid generation we will now take another
example, the opium poppies. They usually have a dark center in the
flowers, the inferior parts of the four petals being stained a deep
purple, or often nearly black. Many varieties exhibit this mark as a
large black cross in the center of the flower. In other varieties the
pigment is wanting, the cross being of a pure white.
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