Abstract
The fine structure of the first metaphase spindle in pollen mother cells of Lilium longiflorum and Magnolia liliflora has been studied by means of the electron microscope. It has been confirmed that the treatment with CdCl2 solution was very efficacious for the preservation of the internal fine structure of the spindle. In ultra-thin sections it has been asserted that the atractoplast is composed of submicroscopic unit fibrils as the dispersed phase, and that a chromosomal fiber is a bundle consisting of many fine fibrils. The surface boundary of the spindle body was partly observed as membrane structure.
The author is grateful to Professor B. Wada for advice and helpful suggestion, and to Dr. N. Tanaka and Mr. S. Sakata for valuable help with the experiments. This work was supported in part by a grant from the Science Research Fund of the Ministry of Education and in part by a grant from the Fuju-kai Research Encouragement Fund.
