from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The central cavity of the gastrula, which ultimately becomes the intestinal or digestive cavity.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A primitive alimentary cavity
from the GNU version of the Collaborative International Dictionary of English
- n. The primitive enteron or undifferentiated digestive sac of a gastrula or other embryo. See Illust. under invagination.
from The Century Dictionary and Cyclopedia
- n. The enteron (which see) in its original or primitive undifferentiated state: opposed to metenteron.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. central cavity of the gastrula; becomes the intestinal or digestive cavity
It becomes even more obvious when a piece of the roof of the archenteron is planted in the blastocoele.
Professor E. Ray-Lankester suggested three years afterwards (1875) the name archenteron for the primitive gut, and blastoporus for the primitive mouth.) (FIGURE.1.36.
Thus a portion of the upper marginal zone of the blastula or early gastrula, or else a piece of the roof of the archenteron of the mature gastrula was planted in the blastocoele of a young gastrula and so brought beneath the ectoderm from the beginning; it was demonstrated that these portions were able to induce neural plate.
Kowalevsky, in 1871, showed that the body-cavity of Sagitta was formed by a division of the archenteron into three parallel cavities, and in 1874 demonstrated the same fact for the Brachiopoda.
With the notochord he homologised the supporting rod in the proboscis of _Balanoglossus_, which like the notochord arises from the dorsal wall of the archenteron, and has a vacuolated structure.
They distinguished in the middle layer two quite distinct elements, the mesoblast proper, formed by the evagination of the walls of the archenteron, and the mesenchyme, formed by free cells budded off from the germ-layers.
There exist, doubtless, homologies of great atavistic importance -- I consider as such, for example, the formation of the cavity of Rusconi [the archenteron] in Ascidians and lower
They form the walls of a new cavity, the enterocoel, which is to be regarded as a nipped-off diverticulum of the archenteron.
Its relation to the Coelom theory lies in the fact that Sedgwick regarded the segmentation of the body as moulded upon the segmentation of the mesoblast, which in its turn, as Kowalevsky and Hatschek had shown, was a consequence of its mode of origin as a series of pouches of the archenteron.
Gastræa; they form the limits of the organism towards the exterior and towards the archenteron.