Über die Karyologie des Radiolars Aulacantha scolymantha und die Feinstruktur seiner Chromosomen

摘要: 1. Cachon-Enjumet's (1961) attempt to interpret the nuclear division of radiolarian, Aulacantha scolymantha, as a typical, though superficially modified mitosis is subject criticism. There no evidence for differences between numerous chromosomes this species. The identification nucleolus organizing inconclusive since supposed nucleoli contain DNA and are obviously due disintegration chromosomes. No existence true was found. Instead, all unusually great amounts RNA. Evidence chromosomal on basis arm length kinetochore position equally inconclusive. localized points spindle fiber attachment could be identified in electron microscope. Attention drawn number artefacts connection. It concluded that Cachon-Enjumet did not succeed bringing forth any new conclusive arguments against Grell's (1953) hypothesis homologous genetically equivalent. 2. The basic ultrastructural component radiolarian fibril about 80 A thickness. 3. A component, consisting an axial complex demonstrable after treatment sections with both uranyl lead ions, described. So far, it unknown if represents special feature which may have some bearing cytogenetic peculiarities species. 4. Within specialized „spindle plasma“ excluding formed elements like Golgi vesicles mitochondria, tubular fibers been identified. Their confined kinetochores. seems conform type „diffuse“ described from various insect orders by technique light microscopy.