Abstract
Electron microscopic studies on the substructure of chromatin were carried out using chromosomes in the first meiotic metaphase from pollen mother cells of Tradescantia reflexa. The chromosomes were composed of 300Å chromatin threads formed by coiling of 100Å chromatin thread. The 100Å chromatin threads contained globular structures of about 70Å diameter. The location of DNA, protein and RNA were studied by treatment of the chromosomes with DNAase, 0.25N HCl containing 2M NaCl and RNAase.
