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The structure of theK π = 2+ gamma vibrational bands and the quasi-gamma bands of even-Z-even-N nuclei is investigated on a global scale, vis-a-vis the variation of band head, the moment of inertia of the band and the odd-even spin staggering. The variation withN andZ and with spinJ of the odd-even spin energy staggering index is studied and a unified view of the same is presented.

Development of the shoot apex inSesamum indicum Linn, andEruca sativa Mill, was followed from the mature embryo to early reproductive stages. The shoot apex shows an age-related increase in size until the reproductive phase sets in. In both species, the epicotyl apex is flat with a single tunica layer covering a homogeneous corpus. InSesamum the 3-day old seedling apex shows the early stages in the establishment of cytohistological zonation in the corpus leading to well-established zonation in the dome-shaped 4-day old seedling apex. InEruca the maximal stage of the 3-day old seedling apex is a low dome and zonation in the corpus is well established in the 4-day old apex. Establishment of zonation seems to be related to the size of the apex in the first place and probably to the shape also as applied to particular species. The sequence of establishment of zones is, the peripheral zone first followed by the corpus mother cells and pith meristem zones almost simultaneously.

The shoot apex ofNymphaea stellata Willd. shows a tunica-corpus organization with a cytohistological zonation. The tunica is single-layered and the corpus exhibits three zones, the corpus mother cells zone, the flanking zone and the pith-rib meristem zone. The plastochron is divided into five stages based on the plastochron index—the minimal, early post-minimal, late post-minimal, pre-maximal and maximal. A cambium-like zone is developed proximal to the corpus mother cells zone in apices at the post-minimal stages, which contributes to the increase in height of the apex.

Root apical organisation inAnnona squamosa, Artabotrys odoratissimus,Polyalthia longifolia, Nigella sativa, Ranunculus sceleratus, Clematis triloba andMichelia champaca falls into two types: Type I—Annona,Artabotrys, Polyalthia,Michelia andNigella, show a common group of initials around which the derivatives differentiate into the root cap, epidermis, cortex and central cylinder. Type II—Ranunculus andClematis, show discrete initials for the plerome, periblem, dermocalyptrogen and columella. The arboreal species investigated show a common group of initials and the herbaceous ones (exceptNigella) discrete initials at the root apex. This may be of phylogenetic significance.

Intensity distribution in the diffraction images of truncated, one-dimensional periodic objects has been investigated for an optical system having a circular aperture with an amplitude filter. Incoherent square, sine and triangular-wave objects have been considered with various number of cycles. It has been found that in the presence of amplitude shading, the number of periods is less than in case of a system without shading.