. A textbook of botany for colleges and universities ... Botany. 748 ECOLOGY possess erect or orthotropic and horizontal or plagiotropic shoots, which obviously are correlated, since the removal of the former causes the latter to become erect; the presence of the erect shoot appears to inhibit the horizontal shoot from becoming erect. The reference of phenomena to correlation, or for that matter to inherent factors, does not explain them. The use of such indefinite terms is mystifying rather than illuminating, and ex- planations must be sought in actual under- lying causes. However, terras lik
. A textbook of botany for colleges and universities ... Botany. 748 ECOLOGY possess erect or orthotropic and horizontal or plagiotropic shoots, which obviously are correlated, since the removal of the former causes the latter to become erect; the presence of the erect shoot appears to inhibit the horizontal shoot from becoming erect. The reference of phenomena to correlation, or for that matter to inherent factors, does not explain them. The use of such indefinite terms is mystifying rather than illuminating, and ex- planations must be sought in actual under- lying causes. However, terras like correla- tion and inherent causes may be useful temporarily, as serving to denominate these particular regions of our ignorance. Regeneration. — In most plants the termi- nal buds are stronger than the others, and they develop into vigorous shoots (figs. 952, 953); the upper lateral buds develop into less vigorous shoots, and the lower lateral buds usually remain undeveloped. Such plants are characterized by excurrent branch- ing. In some cases (as in the lilac) the lateral buds are the stronger, and their continued development results in deliquescent branch- ing. If a terminal bud of an excurrent shoot is injured or removed during development, one or more lateral buds, which other- wise might have remained latent, grow out into shoots (figs. 873, 1055). Such a re- placement by similar organs of an organ that has been removed, or whose growth has been checked, is known as regeneration. In animals a lost part commonly is regener- ated at the place of severance. This rarely occurs in plants, possibly because of the presence of latent buds. In roots and in some leaves (as in Cyclamen), where there are no such latent buds, the lost part may be restored at the cut surface, as in animals (p. 503); the regeneration of a lost part at the cut surface may be termed Fig. 1071. — Regeneration in the scarlet runner bean (Phaseolus multiflorus); the epicotyl of a seedling
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