Rhabdome-bearing cells within the corpus cardiacum of Melanogryllus desertus (orthoptera, gryllidae).

Cells with rhabdomeric structures characteristic of photoreceptor cells occur within the corpus cardiacum of Melanogryllus desertus. These cells are few in number and are larger than intrinsic secretory cells. Each has numerous rhabdomeric microvilli forming a rhabdome within the cell. The arrangement of large mitochondria under the rhabdomeric microvilli around the dilated endoplasmic reticulum membranes and multivesiculated bodies is distinctive. Rhabdome cells have synaptic contacts with the numerous neurosecretory axons that surround them. Other neurosecretory axons come in close contact with the membranes of microvilli.