. Botany for agricultural students . Botany. 530 EVOLUTION The mutations involved various kinds of characters. One of the new forms, Oenothera brevistylis, had, among other distinc- tive characters, a much shorter style than the Oenothera La- marckiana. Another new form, Oenothera la£vifolia, had smooth leaves and much prettier foliage than the parent type, and its petals were not notched. One of the finest and rarest of the mutants was the Oenothera gigas {Fig. 4-73), which was stronger, bigger, and more heavily built thaia the parent. Others of the new forms differed from the parent in other
. Botany for agricultural students . Botany. 530 EVOLUTION The mutations involved various kinds of characters. One of the new forms, Oenothera brevistylis, had, among other distinc- tive characters, a much shorter style than the Oenothera La- marckiana. Another new form, Oenothera la£vifolia, had smooth leaves and much prettier foliage than the parent type, and its petals were not notched. One of the finest and rarest of the mutants was the Oenothera gigas {Fig. 4-73), which was stronger, bigger, and more heavily built thaia the parent. Others of the new forms differed from the parent in other char- acters. As to what a new form is, can be determined only by breeding it and its parents in pedigree cul- tures. A new form may result from crossing be- tween two parents with different characters and, therefore, be a hybrid. The new form may be due to the fact that the parent is a hybrid or de- scendant of a hybrid and consequently does not breed true, thus producing offspring different from the parent type. If the parents are pure, and the new form is not a hybrid, it must be a mutant or a fluctuating variant. If it breeds true, it is a mutant; other- wise, it is a fluctuating variant. By growing the parents of the new forms in pedigree cultures for a number of generations, he found that they bred true, except for the new forms which occasionally appeared, and concluded that the parents were pure. Since the parents of the new forms were carefully pollinated artificially, so as to prevent crossing between parents differing in characters, the new forms were not the result of hybridizing, They were either. Fig, 473. —The Giant Evening Prim- rose (Oenothera gigas), one of the mutants from Lamarck's Evening Primrose, After De Vries,. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Martin, John N. (John
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1919
