Day 55 Conceptus.

Day 55 Conceptus.
The amniotic vesicle (6.5 cm) is enclosed by the allantois. Cotyledons are developing in 4 rows of 15 on the external surface of the allantoic membranes. They tend to be largest near the amnion where the blood supply is the most developed. [5 cm squares]

Chenoweth PJ (2012)