Why do single-crooked creatures look exactly like the parent cell?

 The indigesti- size until the whole interior is pretty well filled ble remainder is then ... little, and in one place is bent into the form of a mouth—very much like that of a beaker. ... One can see the creature go through the same movements if the vessel in ... Each of these parts enlarges and becomes exactly like the parent animal.

Explanation:

the scientific method.