Stage 16 (21 hrs)
Late gastrula stage
Drown by T. Iwamatsu
(Abbr. em: embryonic body)
Stage 16 (21 hrs 0 min) Late gastrula stage:
The blastoderm covers 3/4 of the yolk sphere, and the em- bryonic shield (body) becomes more clearly visible as a narrow streak. The enveloping layer expands uniformly over the yolk sphere until this stage [18].