We will choose the latter, and take the sugarcorn in comparison with the
ordinary or starch producing forms for our starting point. Both sugar-
and starch-corns have smooth fruits when ripening. No difference is to
be seen in the young ripe spikes. Only the taste, or a direct chemical
analysis might reveal the dissimilarity. But as soon as the spikes are
dried, a diversity is apparent. The starchy grains remain smooth, but
the sugary kernels lose so much water that they become wrinkled. The
former becomes opaque, the latter more or less transparent. Every single
kernel may instantly be recognized as belonging to either of the types
in question, even if but a single grain of the opposite quality might be
met with on a spike. Kernels can be counted on the spike, and since
ordinary spikes may bear from 300-500 grains and often more, the
numerical relation of the different types may be deduced with great
accuracy.
Coming now to our experiment, both starchy [289] and sugary varieties
are in this respect wholly constant, when cultivated separately. No
change is to be seen in the spikes. Furthermore it is very easy to make
the crosses. The best way is to cultivate both types in alternate rows
and to cut off the staminate panicles a few days before they open their
first flowers. If this operation is done on all the individuals of one
variety, sparing all the panicles of the other, it is manifest that all
the plants will become fertilized by the latter, and hence that the
castrated plants will only bear hybrid seeds.
The experiment may be made in two ways; by castrating the sugary or the
starchy variety. In both cases the hybrid kernels are the same. As to
their composition they repeat the active character of the starchy
variety. The sugar is only accumulated as a result of an incapacity of
changing it into starch, and the lack of this capacity is to be
considered as a retrogressive varietal mark. The starch-producing unit
character, which is active in the ordinary sorts of corns, is therefore
latent in sugar-corn.
In order to obtain the second generation, the hybrid grains are sown
under ordinary conditions, but sufficiently distant from any other
variety of corn to insure pure fertilization. The several individuals
may be left to pollinate [290] each other, or they may be artificially
pollinated with their own pollen.
Public-domain text, read in full here on John Shaqi.
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