Abstract
1. The spindle figure treated with metal salt solutions shows its outline without failure and is filled up densely with innumerable spindle fibers.
2. The distal ends of large chromosomes hitherto considered as lying in the cytoplasm are found to be always enveloped with a spindle surface membrane, when cells are alive.
3. The multipolar spindle in pollen mother cells appears irregularly in its outline but is clearly distinguished from the cytoplasm, and reveals that it is nuclear in origin.
4. In the materials used in this study no essential difference is found in the structure of the karyokinetic spindle between plant and animal cells.
5. The preservation of the submicroscopic structures of the spindle in preparations is discussed on the case of fixation and of coagulation.
