The pore or opening leading into the hole of invagination or archenteron
- the orifice in to the archenteron
- The pore or opening leading to the cavity of invagination, or archenteron.
(letter.) The pore or orifice leading in to the hole of invagination, or archenteron.
There are, however, variations in regard to the relation of the blastopore to the mouth and to the anus which are probably modifications of the original process described above.