Figure 3.

Endospore development in an Arthromitus sp. from Reticulitermes tibialis; n = genetic material. (a) Early stage in spore formation. (b) Maturing spore and enigmatic tubular body (arrows) apposed to inner surface of membrane. (c) Growing filament still covered with spore coat (SC) material. The possibility that these tubular membrane connectors (arrowheads) are composed of filament temperature-sensitive Z protein (Ftsz) needs investigation. (d) Endospore in which nucleoid is apposed to the inner surface of the proteinaceous thickening of the membrane (arrowheads), transverse section comparable to b and c. (Bar = 1 μm.)