<P> However , the idea that all cells come from pre-existing cells had in fact already been proposed by Robert Remak ; it has been suggested that Virchow plagiarized Remak and did not give him credit . Remak published observations in 1852 on cell division , claiming Schleiden and Schawnn were incorrect about generation schemes . He instead said that binary fission , which was first introduced by Dumortier , was how reproduction of new animal cells were made . Once this tenet was added , the classical cell theory was complete . </P>
who proved that cells come from other cells
Robert Remak