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Updated: June 2, 2025
Specific and varietal characters may occur together in many of the several forms, but nothing is as yet accurately known as to their behavior in pure fertilizations. Constancy and segregation are thrown together in such a manner that extreme variability results, and numerous beautiful types may be had, and others may be expected from further crosses.
They have the same varietal mark, but belong to different species of barley. These are differentiated according to the number of the rows in which the grains are seen on the spikes. These numbers may be two, four or six, giving rise to the specific names of Hordeum distichum, tetrastichum and hexastichum.
For my crosses I have taken the dark-centered "Mephisto" and the "Danebrog," or Danish flag, with a white cross on a red field. The second year the hybrids were all true to the type of "Mephisto." Once more the flowers were self-pollinated and the visits of insects excluded. The recessives now gave only recessives, and hence we may conclude that the varietal marks had returned to stability.
=Varietal names= and descriptions mean something quite different in the case of plants like the tomato, which are propagated by seed, from what they do with plants like the apple and strawberry, which are propagated by division. In the latter case all the plants of the variety are but parts of the primal origination, and so are alike.
Coming now to the other side of the question, we may consider those cases of reversion which have been recorded from time to time, and which always have been considered as direct proofs of the varietal character of the reverting form.
The best proof perhaps, of the unfavorable influence of external conditions for slightly deteriorated deviations is afforded by variegated leaves. Many beautiful varieties are seen in our gardens and parks, and even corn has a variety with striped leaves. They are easily reproduced, both by buds and by seeds, and they are the most ordinary of all varietal deviations.
Many old crosses must be repeated and studied anew, taking care of the purity of the cross as well as of the harvesting of the seeds. Many supposed facts will be shown to be of doubtful validity. New facts have to be gathered, and in doing so the distinction between specific and varietal marks must be taken strictly into account.
This combination is to be the basis of our discussion. It is liable to be produced all of a sudden. This assertion is proved by its occurrence as a varietal mark in one of our most ordinary cultivated plants. It is the group known as Croton, belonging to the genus Codiaeum.
But though most of these forms are very ornamental and abundant in parks and gardens, little is as yet known concerning the origin of their varietal attributes and their constancy, when propagated by seeds. Besides the ray-florets and the colors, there are of course a great many other characters in which varieties may differ from their species.
Much of their variability, however, is due to hybridism, and the combination of characters previously separate has a value for the breeder nearly equal the production of really new qualities. Nevertheless there is no doubt that some new characters appear from time to time. In a previous lecture we have seen that varietal characters have many features in common.
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