SYNOPSISThe germ cells of the arthropodsOniscus asellus, Petrobius maritimus, andSchistocerca gregariahave been studied during spermatogenesis by a variety of modern cytochemical and enzyme‐blocking techniques. The chemical composition of the Golgi bodies, mitochondrial nebenkerne, nucleus, and cytoplasm has been determined and found to have some variation in distribution. The chemical composition of the centriole could not be determine