PHENOMENA OF HETEROTYPIC DIVISION IN THE POLLEN MOTHER‐CELLS OF A TETRAPLOID FORM OF RUMEX SCUTATUS VAR. TYPICUS*

Meiosis in Some Species and a Hybrid of Paeonia

“…I3) is significant in its resemblance to the nucleoli of larger nuclei. This would tend to support the theory of Fikry (1930) that the nucleolus is a reservoir of chromatin material. Fronm a consideration of the above data, the conclusion can be reached that the two meiotic abnormalities which are of the greatest significance in regard to species evolution in Paeonia are fragmentation and chromatid fusion.…”

Cytological Investigations of Rice Varieties

“…So long as the continuous spireme theory held sway, it was usually held that the nucleolus functioned as a repository of chromatin material; it stored this material during telophase and resting stage and used it up during prophase. Fikry (1930) and Dermen (1933) pointed out the difficulties in explaining the passage of nucleolar material to or from the chromosomes when, as appeared to be the case, the spireme was not continuous. We have seen that in rice the nucleoli, one or two in number, are closely connected with a particular pair of chromosomes at a definite position on them.…”

Zytologische Studien in der GattungPopulus L.

“…FIKRY (1930) (CAT-CHESIDE, 1934;Fig. Doch ist es denkbar, dasz ein Nukleolus eine oder mehrere wirkliche Knospen oder Protuberanzen bilden kann, obwohl auch bier an die M6glichkeit gedacht werden musz, dasz es sich um mehrere einzelne Nukleoli handelt, deren SaT-(;hromosomen nicht oder sehr schwer zu erkennen sind.…”