progaster

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 Rudolf Schmid

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 Ernst Heinrich Philipp August Haeckel 1876

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

The Evolution of Man — Volume 1 Ernst Heinrich Philipp August Haeckel 1876

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 Ernst Heinrich Philipp August Haeckel 1876

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 Ernst Heinrich Philipp August Haeckel 1876

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

The Evolution of Man — Volume 1 Ernst Heinrich Philipp August Haeckel 1876

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 Ernst Heinrich Philipp August Haeckel 1876