Area pellucida
the translucent central area of the blastoderm of birds and reptiles within which the embryo develops.
Historical Examples
From the middle of this sickle a process next grows forward into the area pellucida.
The Works of Francis Maitland Balfour, Volume 1 Francis Maitland Balfour
They are almost entirely confined to the posterior part of the area pellucida, and give rise to the opacity of that part.
The Works of Francis Maitland Balfour, Volume III (of 4) Francis Maitland Balfour
Section through anterior part of area pellucida in front of embryonic shield.
The Works of Francis Maitland Balfour, Volume IV (of 4) Francis Maitland Balfour
In the course of further growth the area pellucida soon becomes pyriform, the narrower extremity being the posterior.
The Works of Francis Maitland Balfour, Volume III (of 4) Francis Maitland Balfour
The primitive streak is however the most interesting structure in the area pellucida at this stage.
The Works of Francis Maitland Balfour, Volume 1 Francis Maitland Balfour
The epiblast spreads rapidly over the white yolk, and the area pellucida also increases in size.
The Works of Francis Maitland Balfour, Volume 1 Francis Maitland Balfour
Junction between the white-yolk spheres and the hypoblast cells at the passage from the area pellucida to the area opaca.
The Works of Francis Maitland Balfour, Volume IV (of 4) Francis Maitland Balfour
In the region of the area pellucida there is placed below the epiblast a more or less irregular layer of cells.
The Works of Francis Maitland Balfour, Volume 1 Francis Maitland Balfour
Outside the area pellucida, an area vasculosa has become very well defined.
The Works of Francis Maitland Balfour, Volume III (of 4) Francis Maitland Balfour
In surface views the primitive streak often appears to stop short of the hinder border of the area pellucida.
The Works of Francis Maitland Balfour, Volume 1 Francis Maitland Balfour
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anthropological or sociological research intended to gather and relate data on various aspects of a geographical region and its inhabitants, as natural resources, history, language, institutions, or cultural and economic characteristics; a field investigation into human ecology.
- Area vasculosa
that part of the area opaca in which the blood cells and vessels are formed. Historical Examples Outside the area pellucida, an area vasculosa has become very well defined. The Works of Francis Maitland Balfour, Volume III (of 4) Francis Maitland Balfour Their development is completed on the second day; and the region through which […]
- Area vitellina
the nonvascular part of the area opaca surrounding the area vasculosa.
- Areal
any particular extent of space or surface; part: the dark areas in the painting; the dusty area of the room. a geographical region; tract: the Chicago area; the unsettled areas along the frontier. any section reserved for a specific function: the business area of a town; the dining area of a house. extent, range, or […]