A Membranous Apparatus in a Flagellate, Tritrichomonas Augusta

Cultures of Tritrichomonas augusta, generously provided by Professor William Balamuth, were grown in Diamond's medium (6) modified by omission of agar. Because the organisms are anaerobic, the culture tubes were sealed with a mixture of vaseline and paraffin to exclude oxygen. 4-day cultures were fixed for 2 hr at 4°C in 5% glutaraldehyde-2% acrolein in 0.1 M cacodylate buffer with a final pH of 7.3. The organisms were then washed for 2 hr in cold 0.2 M sucrose-0.1 M cacodylate buffer and postfixed for 2 hr in 2%o osmium tetroxide in 0.1 M cacodylate buffer at 4°C. They were dehydrated in ethanol followed by two changes of propylene oxide, embedded in Epon, sectioned with a diamond knife on a Porter-Blum MT 1 ultramicrotome, stained with aqueous uranyl acetate and Reynolds's lead citrate, and examined in an RCA EMU 3F electron microscope.