Title
Page 08 – Transverse sections of the stem of an 8-months-old seedling
Creator
Date
c. 1940
Format
Description
Fig. 10 (following)
Series of transverse sections of the stem of an 8-months old seedling at different levels to show the development of the axis. X50.
Figs. a-c, cut at levels just above apical growing region to show arrangement and comparative size of youngest leaves (2nd section cut at level 90 /ᵘ below 1st, and 3rd, 75 /ᵘ below 2nd).
Fig. d, cut at level of tip (a) of apical growing region to show base of youngest (l) and next to youngest (l₁), etc., leaf primordia (section cut at level 30 /ᵘ below preceding section).
Fig. e, cut at level of promeristematic "cap" (pm) in apical growing region. Notice that most vascular bundles at this level are cut in cross section. Bundle l (b₁) forms the trace for leaf l; 2-4, incl., for leaf l₁; and 5-11, incl., for leaf l₂, etc. (section cut at level 60 /ᵘ below preceding section).
Fig. f, cut at level to show first indication of presence of specialized meristematic tissue (sm) in form of ring in cross section. Notice that central bundles, forming traces of youngest leaves, are cut obilquely and longitudinally (section cut at level 60 /ᵘ below preceding section).
Fig. g, cut at level 60 /ᵘ below section 6, and
Fig. h, cut at level 120 /ᵘ a below section 7, to show "ring" of specialized meristematic tissue (sm) separating stele (s) from cortex (c). Notice Stelar bundles passing out through the "ring" as leaf traces.
Fig. i, cut at level of root initiation. Section cuts base of root (r) tangentially (section cut at level 120 /ᵘ below preceeding section).
Series of transverse sections of the stem of an 8-months old seedling at different levels to show the development of the axis. X50.
Figs. a-c, cut at levels just above apical growing region to show arrangement and comparative size of youngest leaves (2nd section cut at level 90 /ᵘ below 1st, and 3rd, 75 /ᵘ below 2nd).
Fig. d, cut at level of tip (a) of apical growing region to show base of youngest (l) and next to youngest (l₁), etc., leaf primordia (section cut at level 30 /ᵘ below preceding section).
Fig. e, cut at level of promeristematic "cap" (pm) in apical growing region. Notice that most vascular bundles at this level are cut in cross section. Bundle l (b₁) forms the trace for leaf l; 2-4, incl., for leaf l₁; and 5-11, incl., for leaf l₂, etc. (section cut at level 60 /ᵘ below preceding section).
Fig. f, cut at level to show first indication of presence of specialized meristematic tissue (sm) in form of ring in cross section. Notice that central bundles, forming traces of youngest leaves, are cut obilquely and longitudinally (section cut at level 60 /ᵘ below preceding section).
Fig. g, cut at level 60 /ᵘ below section 6, and
Fig. h, cut at level 120 /ᵘ a below section 7, to show "ring" of specialized meristematic tissue (sm) separating stele (s) from cortex (c). Notice Stelar bundles passing out through the "ring" as leaf traces.
Fig. i, cut at level of root initiation. Section cuts base of root (r) tangentially (section cut at level 120 /ᵘ below preceeding section).