1. Ultrastructurally, these thecal cells possess organelles characteristic of steroid-producing cells: mitochondria with tubular cristae and agranular endoplasmic reticulum.

2. Leaf mesophyll cells which had recovered from the bacterial toxemia appeared similar ultrastructurally to mature healthy cells, although they remained smaller.

3. Processes of dedifferentiation are characterized ultrastructurally by a decrease of the tonofilament system, increase of simple desmosomes, amoeboid transformation of cell surfaces with increasing interdentation as in glandular epithelia and also by partial separation of basal cells from the basement membrane.