An Acid Mucopolysaccharide in Cockroach Ganglia

Abstract

IN a recent histochemical investigation of the neurones and connective tissues of the meso- and meta-thoracic ganglia of the cockroach, Periplaneta americana¹, it was noticed that an area surrounding the central mass of nerve fibres stained metachromatically with toluidine blue. The region separates the neurones and connective tissue sheath from the main mass of nerve fibres. There is no comparable region in the interganglionic connectives or peripheral nerves. This seems at present to be a structure peculiar to Periplaneta and other cockroaches; a similar region has been seen after staining with toluidine blue in Blaberus craniifer, Blatta orientalis, Blattella germanica and Diploptera punctata. No such region is found in insects of other orders which have been studied histochemically, for example, Ephestia kühniella, (Richards, A. G., personal communication), Locusta migratoria (unpublished observations) and sucking lice².