caudalward

The two cavities in the general mesoderm unite on the ventral aspect of the gut and form the pleuro-peritoneal cavity, which becomes continuous with the remains of the extra-embryonic celom around the umbilicus; the two cavities in the pericardial area rapidly join to form a single pericardial cavity, and this from two lateral diverticula extend caudalward to open into the pleuro-peritoneal cavity (Fig. 54).

I. Embryology. 13. Development of the Body Cavities 1918

As development proceeds the dorsal end of the septum is carried gradually caudalward, and when it reaches the fifth cervical segment muscular tissue with the phrenic nerve grows into it.

I. Embryology. 13. Development of the Body Cavities 1918

This continues to grow caudalward until it opens into the ventral part of the cloaca; beyond the pronephros it is termed the Wolffian duct.

XI. Splanchnology. 3. The Urogenital Apparatus 1918

—In the outer part of the intermediate cell-mass, immediately under the ectoderm, in the region from the fifth cervical to the third thoracic segments, a series of short evaginations from each segment grows dorsalward and extends caudalward, fusing successively from before backward to form the pronephric duct.

XI. Splanchnology. 3. The Urogenital Apparatus 1918

92—The primary arrangement for drainage of the capillaries of the head (Figs. 481, 488) consists of a primary head vein which starts in the region of the midbrain and runs caudalward along the side of the brain tube to terminate at the duct of Cuvier.

V. Angiology. 3. Development of the Vascular System 1918