1. Routes to the replicative double helix: (a) ?On the chemical composition of pyocytes?, Hoppe-Seyler's med. Untersuchungen, 1871;
2. Die histochemischen and physiologischen Arbeiten (Ed.: F. C. W. Vogel), Leipzig, 1897;
3. (b) Arch, Anat. Phys. Phys. Abt. 1889;
4. Die Elementarorganismen, Veit, Leipzig, 1890;
5. (c) What is life?, Cambridge Univ. Press, New York, 1944;