Appearance of “Metallophilic Cytoplasm” as a Prepattern to the Differentiation of Rhizoid in Fern Protonema

1. When rhizoid is differentiated from the protonema of some ferns, Dryopteris varia, Diplazium japonicum, and Blechnum niponicum a special cytoplasm which has a high affinity for metallic ions, called the “metallophilic cytoplasm”, appears at the presumptive part prior to the actual differentiation as a prepattern to the rhizoid formation. 2. In the rhizoid under active elongation, the metallophilic cytoplasm appears in the basal region while in a fullgrown rhizoid it is restricted to the basal end. 3. The metallophilic cytoplasm could not be verified in rhizoids of the sporeling of a moss, Pogonatum inflexum, in root hairs of the seedling of some Angiosperm, Glycine Max, Raphanus sativus, and Triticum vulgare. 4. The metallophilic property appears regardless of the acidity level of the cytoplasm whether it is on the lower or on the higher side of its IEP. Therefore, it seems that it cannot be attributed to the attraction by the cytoplasm of metallic ions caused by difference in electric charge between the two.