The digestive gland of Phyllocaulis soleiformis is a compound tubular gland. The secretory tubules are made up of two main cell types: the digestive cells and calcic cells. The digestive cells are the most numerous, usually columnar, and exhibit three different functional stages: absorptive, secretory and excretory. These cells contain two cytoplasmic granules types and, in the excretory stage, most of the cell is occupied by a large vacuole. The calcic cells occursingly or frequently in groups of two or three, are triangular shaped and have distinct apical granules, and yet calcic histochemical detected granules. In addition, there is a third cell type, without characteristic cytoplasmic granules and which correspond to the undifferentiated cells. The... |