The induction, development, and heritability of fasciations . e i8. INDUCTION, DEVELOPMENT, AND HERITABILITY OF !• ASCIATIONS. Study of fasciation is naturally i^-nniped about these two i^eriods. Thecharacter of the fasciated rosette, with broad, linear heart, .ii^ivino- rise tostems flattened from the base, has been made familiar by de Vries (11). Inthe cultures such rosettes reached a breadth of 3 cm., and the stalk fromone of them produced a vegctative line which eventually measured 38 cm.(plate i). In other cases the first evidence of fasciation in the rosette is abifurcation of the .qrowi
The induction, development, and heritability of fasciations . e i8. INDUCTION, DEVELOPMENT, AND HERITABILITY OF !• ASCIATIONS. Study of fasciation is naturally i^-nniped about these two i^eriods. Thecharacter of the fasciated rosette, with broad, linear heart, .ii^ivino- rise tostems flattened from the base, has been made familiar by de Vries (11). Inthe cultures such rosettes reached a breadth of 3 cm., and the stalk fromone of them produced a vegctative line which eventually measured 38 cm.(plate i). In other cases the first evidence of fasciation in the rosette is abifurcation of the .qrowins region, and two tiny buds sometimes appear evenbetween the cotjdedons. The two types of rosettes are illustrated by plate ii,fiS. 4, and by text-fig-. 1. The fasciation of the flowering- stalks is far more common than that of the rosette andfurnishes the bulk of the material forobservation, as well as for histologicalexamination. Usually the rosetteshave been plants to be kept for otherexperimental purposes, but the latebranches may be cut at will. The. Fig. I.—Raiinannia odorata, bifurcatedrosette. flowering stems studied came mostlyfrom two sets of plants—the wildO. bioinis and the O. critciata in thegarden. There were man\- ring-fasciations in the two groups, thoughthese have been comparatively infre-quently rei^orted. The O. biennis,besides simple fasciations and ring-fasciations, showed on many stems,associated with the banding, an indentation or groove, as represented inplate II, fig. 2, running up the upper half of the stem. The groove becamewider and deeper as the stem flattened. Simple fasciations, ring-fasciati( groove-fasciations occurred together, both on secondary and tertiarybranches of plants of which the main axis had usually been stunted. Twodescriptions may be taken as representative: Plant The plant had ii branches, which were all equal in importance, the maintip having been stunted early in its history. There was consequently no main branc
Size: 1477px × 1692px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublisher, booksubjectplants
