Now, if we take a small cross sectional area, a cross sectional picture of this flagella, and we zoom in and we look at the two dimensional slides, we basically get the following arrangement of microtubules. So it consists of nine doubled pairs of microtubules that create this circular like diagram, circular like arrangement around a section of two central microtubules. And this arrangement of nine to two, known as nine, is known as nine plus two. So this is a very common arrangement inside eukaryotic flagella. It's the nine to two microtubule arrangement. We have nine of these doublets 123-45-6789 that forms a circular arrangement around this central microtubial doublet.