Stage 20 (1 day 7 hrs 30 min)
4 somite stage
Drown by T. Iwamatsu
(Abbr. ev: otic (ear) vesicle rudiment, kv: Kupffer's vesicle)
Stage 20 (1 day 7 hrs 30 min) 4 somite stage:
Apaired placode of otic (auditory) vesicles appears at the posterior regionofthe head. Depressions begin to form at the dorsal surface of the eye vesicles. Three parts of the brain (the fore-, the mid- and the hind-brain) are discernible.