Plate 17
|
PLATE NUMBER |
STAGE |
TIME |
ORIENTATION |
IMAGE |
|
17 |
Small yolk plug stage Embryo stage 13 |
14 h 45 min p.f. |
Dorsal Posterior Ventral |
Parasagittal section |
Anterior
Small yolk plug (advanced Gastrula) stage
The floor of archenteron is made of an epithelial lining of the vegetal yolk sac and its roof is made of involuted superficial cells. The bottle cells also participate in the formation of the lining of the archenteron. There is more mesoderm in the dorsal as compared to the ventral aspect of the blastocyst. The blastopore is narrowed significantly.