AbstractDesert locustcorpora cardiacahave been treated with hydrolytic enzymes in saline solution in order to facilitate separation of individual intrinsic cells. Some of the enzymes digested the basal lamina covering thecorpus cardiacum, and also the intercellular cementing substance. Living neurosecretory cells with axonal projections could be isolated and observed by phase contrast microscopy or by darkfield illumination. By morphological criteria the secretory cells should be characterized as neurons, and two different types of secretory neurons have been identified. Brownian movement of cytoplasmic particles occurs in damaged cells and is regarded as a post mortem phenomenon.