“…These tubules are observed sparsely distributed throughout the entire cytoplasm, but some of them are grouped to form bundles extending from the apical plasma membrane to the basal. These microtubules are quite similar in appearance to those reported in various animal cells (SLAUTTERBACK, 1963;DE THE, 1964;BEHNKE, 1964;SANDBORN, 1964;CLARK, 1965;SILVER, 1965;ARNOLD, 1966;LENTZ, 1967;and others) or in plant cells (LEDBETTER and PORTER, 1963;NEWCOMB and BONNET, 1965;PICKETT-HEAPS and NORTHCOTE 1966). Recently the structural details and nature of microtubles have been studied by GALL (1966), BEHNKE and FORER, (1967) and SHCLARNSKY and TAYLOR (1967).…”