NEUROSECRETORY CELLS IN GANGLIA OF THE ROACH. BLABERUS CRANIIFER

Abstract

1. Three types of neurosecretory cells are found within the thoracic abdominal ganglia of the roach Blaberus craniifer These three cell types may be characterized as follows : type I—contains granules staining deep purple with aldehyde fuchsin, the granules being distributed around the periphery of the cell body and in the axon hillock; type II—the most common neurosecretory cell in the ganglia, contains very small granules staining red with chrome hematoxylin and phloxin, the granules being distributed throughout the cell body; type III—the rarest of the neurosecretory cells observed within the ganglia, contains large droplets staining orange with aldehyde fuchsin. The possible identities or homologies of these cell types with others previously described in insects are discussed.2. Secretory products from all three types of neurosecretory cells have been found within axons in the connectives between ganglia.3. Ligation of the connectives between ganglia reveals that at least neurosecretory products of cell types I and II move in both anterior and posterior directions from the ganglia in which they are produced. Neurosecretion from cells of type III is very rarely seen in connectives and, consequently, its direction of movement could not be established.4. No areas of accumulation for any of the neurosecretions were found within the central nerve cords, and the normal functions of these secretions are not known.