Studies on the neurosecretory system and retrocerebral endocrine glands of Ranatra filiformis Fabr. (Hemiptera), using the technique specific for cystine and or cysteine.

The number of cystine rich neurosecretory cells is about 8-10 in each brain lobe. They are of A-type cells. The lateral cells do not have cystine in their secretion. The cystine rich neurosecretory material is seen stored in the loose tissue of the aorta. The axons storing this material have a beeded structure. A pair of CC and CA, which are situated immediately behind the brain are negative to PA VB. The CA have a superficial network of neurosecretory axons and a little amount of NSM in its intercellular spaces.