1. The cyathium of both species studied begins as a papilla which arises between two bracts. The order of appearance of the parts of the cyathium is as follows: staminate flowers, involucre, ovules, ...

American Journal of Botany, Vol. 35, No. 6 (Jun., 1948), pp. 343-349 (7 pages) The female gametophytes of Hesperocallis undulata Gray and Leucocrinum montanum Nutt. follow the normal type of ...

SEVEN ‘Golden Delicious’ apple clones propagated from buds irradiated at 5,000 r. in a cobalt-60 source were selected for high, intermediate, and low pollen abortion. Pollen abortion was 4.9 per cent ...

MEMBERS of the family Loranthaceæ are characterized by many abnormal features in the development and organisation of the embryo sac, endosperm and embryo 1,2,3. In June 1949, one of us (P. M.) ...

Microscopy image of a PGA at day 8 showing the early tissues supporting the embryo, including the amniotic sac and the yolk sac-like structures, surrounded by (extra-embryonic) mesoderm tissue.

Scientists have discovered that a plant hormone called auxin is responsible for development of the egg cell in a plant's embryo sac. In unraveling this fundamental issue in plant biology, the work ...

A gradient (red) in the concentration of auxin, a plant hormone, determines that only one of the eight undifferentiated nuclei in a plant's embryo sac will become an egg. (In this image, a large ...

Mouse embryonic stem cells (ESCs) and extraembryonic trophoblast stem cells (TSCs) have been combined in a 3D scaffold to generate structures whose morphogenesis is remarkably like that of natural ...