ABSTRACT
In the midgut the dorsal anlage of the pancreas becomes visible at stage 35/36 as an abrupt thickening of its antero-dorsal wall. Immediately anterior to the dorsal rudiment of the pancreas, which is clearly segregated from the adjoining parts by narrow slits at stage 37/38, a thick mass of entoderm has descended from the dorsal wall of the alimentary canal, forming the posterior wall of the stomach. The coiling of the intestinal tube leads to marked displacements of the various sections of the alimentary tract. The posterior portion of the oesophagus curves sharply to the left at stage 41, the rest remains in the median plane, slightly inclining ventrad at stage 43. A rearrangement of the cells of the stomach wall, which started at stage 41, foreshadows the formation of the main gastric glands. The cells situated on the periphery of the rudiment become aggregated into groups with narrow slits appearing between them.
