Luzula and the Mechanism of Chromosome Movements

IBKILLAH structure is one of the fundamental properties of the F spindle of nuclear division.The opinion sometimes put forward tliat the fibrous structure is not ))real)) but only *a lixation :rrtef.nct))cannot be taben seriously.It is true enough that the spindle fibres often are to be seen with a niucli coarsened appearance after bad fixation and that after good iixation there is sometimes very little to be seen of tlic films.But it must equally be realized that the fibrous structure as it is brought out in fixed preparations cannot have arisen out of nothing. can be fairly safe in interpreting it as the result of some kind of submicroscopic librillar structure existing already in the living cell :in11 coarsened by precipitation at fixation.Evidence for the existence of :I fibrous struclure of the spindle in the living cell is given especially by studies with polarized light ( e .