1. Caspersson, T.: Über den chemischen Aufbau der Strukturen des Zellkernes. Skand. Arch. Physiol. (Berl. u. Lpz.)73, Suppl. 8, 1?158 (1936).
2. ?: A universal ultramicrospectrograph for the optical range. Exper. Cell Res.1, 596?598 (1950).
3. Ornstein, L.: The distributional error in microspectrophotometry. Labor. Invest.1, 250?262 (1952).
4. Patau, K., andH. Swift: The DNA content (Feulgen) of nuclei during mitosis in a root tip of onion. Chromosoma (Heidelberg)5, in press.
5. Patau, K., andD. P. Bloch: The stray light error in microspectrophotometry. (In preparation).