protovertebrae

And when the articulation of the somites begins in the sole-shaped embryonic shield, and a couple of protovertebrae are developed in succession, constantly increasing in number towards the rear, these cube-shaped somites (formerly called protovertebrae, or primitive vertebrae) have the appearance of solid dice, made up of mesodermic cells (Figure

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

Nevertheless, there is for a time a ventral cavity, or provertebral cavity, even in these solid "protovertebrae" (Figure

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

The hypoblastic notochord is early embraced by a mesoblastic sheath derived from the protovertebrae.

Text Book of Biology, Part 1: Vertebrata 1906

These pairs of "cubes" of the mesoderm are the first traces of the primitive segments or somites, the so-called "protovertebrae."

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

On the floor of the open belly lie, between the protovertebrae, the primitive aortas, from which five pairs of vitelline arteries are given off.

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