Variable Periodicity in the Rhizoplast of Naegleria Flagellates

Flagellar rootlets, rhizoplasts, and parabasal filaments are periodically banded structures which extend into the cytoplasm from the basal bodies and kinetosomes of flagella and cilia (Pitelka, 1969). In all but a few cases the banding pattern has been assumed to be constant for the rhizoplast of a particular organism. This note reports an electron microscope study of the banding pattern of the rhizoplast of the amebo-flagellate Naegleria gruberi, and presents evidence suggesting that while the organelle is in the cell the period is variable . Isolation of the rhizoplast greatly diminishes this variability.