Preliminary Notes on the Embryology of the Starfish (Asterias Pallida)

The early development of lepas. A study of cell-lineage and germ-layers

“…64), the cleavage plane in the yolk coincides approximately with the sagittal plane of the embryo ; but when one of the primary mesoblasts is anterior or dorsal to its sister cell, the plane of separation between the entoblasts is inclined towards the horizontal, or, if vertical, is oblique to the long axis, as in Figure 63. In all cases it appears to extend from near the plane separating the right and left primary mesoblasts towards the antero-dorsal side of the embryo (Figs. 63,64,65,73).…”