1. The different cell-elements of the egg-tubes, eggs, nutritive cells, and epithelium arise from identical undifferentiated elements situated in the contents of the earliest germ of the egg-tubes.
2. The first formation of the cellular elements present, and the differentiation of the individual compartments of the egg-tube, occur during embryonic and larval life.
3. The undifferentiated elements of the terminal chamber correspond to the embryonic condition, while in post-embryonic time, and even during imaginal life, a new formation of the different kinds of cells takes place.
4. The mode of origin of the different kinds of cells from the undifferentiated elements varies greatly in different insects.
5. From their histological nature, and from the mode of origin of their elements, the most complex egg-tubes and those provided with nutritive compartments are phylogenetically derived from those without such nutritive compartments.
6. The nutritive cells in certain cases originate in the same way and at the same time as the germ-cells, and are therefore to be regarded as germ-cells which have abandoned the function of egg-making, and exchanged it for the production of nutritive material.
7. In the egg-tubes with numerous nutritive compartments the nutritive cells can originate at the same place as the egg-cells, and they afterwards still lie intermingled with these in the beginning or upper part of the egg-tubes.
8. While the capability of egg-making of the germ-cells originally situated in the extremity of the terminal chamber gradually becomes transferred to those at the base of the terminal chamber, and the first transform into nutritive cells, egg-tubes with nutritive compartments at the base may be found.
9. The nutritive cells of certain forms arise independently of the germ-cells and therefore could not have previously originated from them.
10. The epithelium has in all forms nearly the same mode of formation; it everywhere shows a close similarity to the undifferentiated elements of the terminal chamber, out of which it directly develops. As to the fact of formation of epithelium through the germ-vesicles (Keimblaschen), nutritive-cell nuclei, or the so-called “oöblasts,” I could not feel certain.