algae antonie van leeuwenhoek archaea bacteria biochemistry biology cell adhesion cell biology cell division cell nucleus cell signaling cellular differentiation cork cambium digital object identifier endoplasmic reticulum energy flow henri dutrochet johann jacob paul moldenhawer ludolph christian treviranus matthias jakob schleiden metabolism micrographia microscopy organelle prokaryote pubmed central robert hooke rudolf virchow spirogyra theodor schwann virus vitalism