Chromosome Numbers and Dimensions, Species-Formation and Phylogeny in the Genus Carex

JUEL published his study on Carex acuta L. ( C .gracilis I CURT.), this being the first investigation made on the cytology of the genus Carex.JUEL'S work deals principally with the pollendevelopment of the above-mentioned species and, with respect to this process, the studies of the present writer have.merely confirmed his observations, nothing of importance having been found to be added.As to the number of the chromosomes, however, JU&L% work does not give any exact data (cf.below).The next work on the cytology of Carex was that of STOUT (1913), dealing with the chromosomes of C. aquatiZis WG.This author confirms and completes the work of JUEL on the pollen-development and', furthermore, he makes a very thorough study of the whole chromosome cycle, special emphasis being laid on the individuality of the chromosomes and their serial arrangement.As to these two problems, STOUT states that the chromosomes of C. aquatilis can be seen as small spherical bodies, maintaining their individuality and a serial arrangement in all cells and in all stages of development except in synizesis.To these latter statements the present writer wants, however, to make some remarks.In really resting nuclei, such as are found e. g. in the walls of the carpels or in the bracts of the inflorescences, I have not been able to see any chromosomes and hence I suppose that the Presting* stages, studied by STOUT, were in reality interphases (cf.