In 1838 iyo 1839, Schleiden iyo Schwann bilaabay dhiirigelinaya fikradaha in (1) unit aasaasiga ah ee noolaha waa unug iyo (2) in unugyada shaqsi leeyihiin dhammaan sifooyinka nolosha, inkastoo ay ka soo horjeestay fikradda ah in (3) dhammaan unugyada ka iman qaybsanaanta unugyada kale. Thanks to shaqada Robert Remak iyo Rudolf Virchow, si kastaba ha ahaatee, by 1860s ugu noolaa aqbalay dhammaan saddexda mabda'a ee waxa yimid in loo yaqaan aragtida unugyada. aragtida unugyada keentay noolayaasha in ay dib-u-fiirinta noolaha shaqsi sida isku-duwidda ee unugyada shaqsi. saynisyahano badan oo soo baxaya oo duurka ah ee cilmiga cytology, qalabaysan microscopes awood badan oo sii kordhaya iyo hababka dhalmada, xitaa halista unugyada halista ahaa unugyada la heli karo iyo (2) in unugyada shaqsi ay leeyihiin dhammaan sifooyinka nolosha, inkastoo ay ka soo horjeedeen fikradda ah in (3) dhammaan unugyada ka yimaadaan qaybinta unugyada kale.
saamayn qoto dheer oo ku saabsan fikirka noolaha