Cell shape and mitotic spindle formation in the generative cell of Endymion non-scriptus.

A study has been made of the changes in distribution of microtubules within the generative cell of Endymion non-scriptus during prophase. The early prophase cell is characterised by the presence of bundles of microtubules at the cell periphery, in the direction of the long axis. As prophase proceeds, these microtubules decline in number in favour of mitotic spindle fibres. The mechanism of formation of the spindle is described and compared with its counterpart in meristematic tissue. The decline in the peripheral microtubules results in a striking change in the shape of the cell. The importance of this is discussed in terms of the functions of the microtubules and of the nature of the boundary separating the generative and tube cytoplasm.