Figs. 28-29. Transverse sections of the trunk of an embryo on the sixth day after impregnation.
Fig. 28. Through anterior part of trunk (from a slightly older embryo than the other sections of this stage).
Fig. 29. Slightly posterior to fig. 28, shewing formation of segmental duct as a fold of the somatic mesoblast.
Fig. 30. Longitudinal horizontal section of embryo on the sixth day after impregnation, passing through the mesoblastic somites, notochord, and medullary canal.
Figs. 31-34. Transverse sections through an embryo on the seventh day after impregnation.
Fig. 31. Through anterior part of trunk.
Fig. 32. Through the trunk somewhat behind fig. 31.
Fig. 33. Through tail region.
Fig. 34. Further back than fig. 33, shewing constriction of tail from the yolk.