Fig. 6. Distribution of mitotic cells in the developing ChE. (A,B) Representative photomicrographs of sagittally sectioned, mitotically arrested ChEs. Examples of mitotic cells are indicated by arrows. Note that mitotic cells were located throughout the ChE, but lay predominantly apically in the chorionic plate in the early-headfold ChE. (A) Early-headfold ChE that has not yet undergone fusion. (B) 5 s.p. ChE that has undergone fusion. Arrow in the ChE median box indicates an exceptional mitotic cell. Scale bar: 25 µm.