The large axons in Periplaneta are composed of bundles of osmiophobe strands about 0.5 µ. thick which fan out into the body of the nerve-cell. These strands are here termed ‘neurofibrils’; it is suggested that the dictyosomes (Golgi bodies) are concerned in their secretion.
The dictyosomes are well stained by the osmium and ethyl gallate method. Each dictyosome surrounds or is applied to an unstained canal which runs into the cytoplasm and is believed to be continuous with the ‘neurofibrils’ as defined. There are all intermediate stages between thin fusiform sheaths of osmiophil material around the ‘neurofibrils’ and the thick rings or cuffs which form the dictyosomes. The clear canals through the dictyosomes are arranged in the main concentrically around the nucleus in the body of the cell; they commonly converge upon the nerve-fibre in the axon cone.