Endocrine cells in the body wall of the midgut of third instar D. melanogaster stained for CCHamide-2.

A. An overview, showing numerous endocrine cells in the anterior part of the anterior midgut (see Figure 3 for a schematic drawing). Scale bar = 100 µm. B. A closer view of the endocrine cells, showing protrusions (arrow) directed toward the lumen of the gut. Scale bar = 20 µm. C. Close-up of a single endocrine cell. The basal part of the cell is in contact with the body circulation (the border of the gut epithelial cells and body cavity is stippled). Note that these cells are 25-40 µm in length. Scale bar = 20 µm.