from The Century Dictionary and Cyclopedia

  • n. The archenteron, or gastrocœle of an embryo in the gastrula stage.
  • n. In entomology, the anterior edge of the abdomen: a term used by acarologists.


Sorry, no etymologies found.


  • In this form, he says, the progaster is already developed, and its wall is differentiated for the first time into an animal or dermal layer (ectoblast), and into a vegetative or intestinal layer (hypoblast).

    The Theories of Darwin and Their Relation to Philosophy, Religion, and Morality

  • The cavity which is produced in the foetus by this curving is, in each case, the primitive gut (progaster), and its opening the primitive mouth (prostoma).

    The Evolution of Man — Volume 1

  • This is the primitive gut-cavity or the gastric cavity of the gastrula, progaster or archenteron.

    The Evolution of Man — Volume 1

  • The first and oldest organ of all these metazoa is the primitive gut (or progaster) and its opening, the primitive mouth

    The Evolution of Man — Volume 1

  • As in all the other animals that form an archigastrula, the whole body is nothing but a simple gastric sac or stomach; its internal cavity is the primitive gut (progaster or archenteron, Figure 1.38 g, 1.35 d), and its aperture the primitive mouth (prostoma or blastoporus, o).

    The Evolution of Man — Volume 2

  • I give the name of primitive gut (progaster) and primitive mouth

    The Evolution of Man — Volume 1

  • In this intermediate stage there are two cavities in the embryo -- the original cavity (blastocoel) which is disappearing, and the primitive gut-cavity (progaster) which is forming.

    The Evolution of Man — Volume 1


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