File:Cyclopedia of American horticulture - comprising suggestions for cultivation of horticultural plants, descriptions of the species of fruits, vegetables, flowers, and ornamental plants sold in the (20825556675).jpg

Title: Cyclopedia of American horticulture : comprising suggestions for cultivation of horticultural plants, descriptions of the species of fruits, vegetables, flowers, and ornamental plants sold in the United States and Canada, together with geographical and biographical sketches
Identifier: cyclopediaofame04bail (find matches)
Year: 1906 (1900s)
Authors: Bailey, L. H. (Liberty Hyde), 1858-1954; Miller, Wilhelm, 1869-
Subjects: Gardening; Horticulture; Horticulture; Horticulture
Publisher: New York : Macmillan
Contributing Library: NCSU Libraries
Digitizing Sponsor: NCSU Libraries

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vane 2641. Kinds of i VARIEGATION plant, and causing the changes known as variegation. Investigations conducted by the writer on the so-called mosaic dis- ease of tobacco, which is a form of variegation, and also on many other forms of ordinary variega- tion, show quite conclusively that the disease is not caused by micro- organisms, but is due to a de- ranged condition of the nutrition of the cells. Without going into the details of the matter, it may be said that the condition is charac- terized physiologically by a marked incn a^c in tlic nxidation processes in tlir .-.ll^. i-an^r.l by the presence <<t an alin.iiiiial aiia.uut, or an ab- normal a.iivity, ..f oxidizing fer- ment in the protoplasm. This fer- ment prevents the movement of food substances, especially starches and nitrogenous materials. The decrease of the latter is especially marked, and it is probably on ac- count of the lack of sufficient ni- trogenous food that the cells do not develop normally. The young growing buds and dividing cells require highly organized albumi- noid foods. They do not make use, to any extent, during the pro- cess of growth and cell division, of the ordinary nitrates which are built up into nitrogenous foods by the mature cells. The oxidizing ferments, though normal constitu- ents of all cells, i.ieieiit, when they become exee-si\el\ aeine. the proper nutriti"ii ..f tlie .li\i(Iing cells, and it is a einin,,, fart that when these ferim nis are e\ii-;ieted from plant ti--iies and mieeted into the youiii; l.iel- ni' 1). althy tissues, they will, m the ease of tobacco at least, cause the buds so treated to develop into variegated shoots. The ferment in question passes readily through the cell-walls of the plants and it thus be- comes evident how such changes could be trans- mitted by grafting and budding, though no para- sitic organisms of any kind are connected with the matter. Another method of producing variegation of tobacco is by cutting the plant back severely during rapid growth. The new shoots have to develop with a small sup- ply of elaborated nitrogenous food, the larger part being removed in the severe cutting back. Shoots thus developed nearly always show variegation. The same thing is true of many other plants, espe- cially the potato, tomato, mulberry, etc. In fact, it appears that a plant is likely to show variegation whenever it is so treated that the growing buds or the forming buds, or the seeds, have to develop un- dersuch conditions that the ferment content of the cells is increased beyond the normal amount, and the reserve foods stored are in small amount. These changes must,^ therefore, be considered as pathological in their nature, as the vitality and

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