This bend becomes dilated into a pouch, which constitutes the entodermal cloaca; into its dorsal part the hind-gut opens, and from its ventral part the allantois passes forward.
This bend becomes dilated into a pouch; into its dorsal part the hind. Gut opens. The allantois passes forward. This is from its ventral part. A pouch constitutes the entodermal cloaca.