1. The mid-gut epithelium of Ephestia is derived from cephalic and caudal mesendoderm rudiments which are proliferated from the germ-band independently of the stomodaeal and proctodaeal invaginations.
2. The oesophageal valve is formed by the backward growth from the blind end of the stomodaeum of six tubules, which later in a slightly altered form extend into the cavity of the mid-gut to form the valve of the larva.
3. The stomodaeum and proctodaeum are purely ectodermal.
4. The malpighian tubules are ectodermal.