 He did not suggest a potential function . In 1838 , Matthias Schleiden proposed that the nucleus plays a role in generating cells , thus he introduced the name " cytoblast " ( cell builder ) . He believed that he had observed new cells assembling around " cytoblasts " . Franz Meyen was a strong opponent of this view , having already described cells multiplying by division and believing that many cells would have no nuclei . The idea that cells can be generated de novo , by the " cytoblast " or otherwise , contradicted work by Robert Remak ( 1852 ) and Rudolf Virchow ( 1855 ) who decisively propagated the new paradigm that cells are generated solely by cells ( " Omnis cellula e cellula " ) . The function of the nucleus remained unclear . 
