Prochromosomes and Supernumerary Chromosomes in Rhinanthus minor Ehrh.

Abstract

THE resting nucleus of Rhinanthus minor Ehrh. is characterized by the presence of a variable number of irregular bodies which stain with Feulgen's stain. These bodies were described as occurring in the genus Alectorolopus (= Rhinanthus) by Witsch¹, who regarded them as fused chromocentres. There are usually four to eight of the bodies in the resting nucleus although the number varies between one and fourteen. They are visible under certain conditions in the living cell and cannot therefore be regarded as artefacts due to fixation. There is usually one nucleolus (rarely two) in the resting nucleus. Each nucleolus is closely appressed at one or more points to one or more of the stainable bodies. The connexion is such that, where a single nucleolus is present, it is sometimes pulled into a spindle shape, more rarely a triangle or rectangle, the two, three or four points of contact with the stained bodies representing the respective apices of these figures.