Fig. 8.

Acid-treated fibre cable of T. × glauca observed with a polarized light microscope equipped with crossed polars and a full-wave plate compensator. (A) The long axis of the fibre cable was oriented parallel to the slow axis of the compensator. The blue additive colour indicates that the cellulose microfibrils were parallel to the long axis of the fibre cable and the slow axis of the full-wave plate. (B) The long axis of the same fibre cable was oriented perpendicular to the slow axis of the compensator. The yellow subtractive colour indicates that the cellulose microfibrils were parallel to the long axis of the fibre cable and perpendicular to the slow axis of the full-wave plate.