Warner and Satir (1974) described the structure of a flagellum as seen under Electron Microscope. According to them various microtubules extending from the base to the tip of the flagellum construct the basic frame work of a flagellum. These are altogether eleven microtubules of which nine are situated at the periphery and two at the centre forming a (9+2) arrangements. All the fibrils are enclosed within a protoplasmic sheath continuous with the cell membrane. The nine peripheral fibrils and two central fibrils constitute the axonome.
Each peripheral tubule is composed of two sub-fibrils namely subfibrils namely subfibril A and subfirbil B. Sub fibrils A and B are also connected by very short arms. All the microfibrils of axoneme are composed of tubulin dimmer. Each dimer is again formed of two monomers namely ? and ? monomers. Each subfibril of the centre is composed of thirteen protofilaments. The central two fibrils are covered by a membrane and the peripheral fibrils are connected with the membrane through radially arranged spoke-like arms. The energy required for flagellar movement comes from ATP.