Studies on the Structure of Cytoplasmic Basophilia V. Electron Microscopic Observations of EndoplasmicBasophilia

From the analysis of the basophilic organella in fixed cells, using the polarizing microscope the author concluded that the ground structure of the organella should be composed of fibrous proteins attached with lipid molecules perpendicular to their long axes. But there is a problem left to be clarified whether or not the analysis on molecular arrangement by polarizing microscope on fixed cells gives the picutre of moleclar structure on each basophilic organella in living cells. Then the morphologic picture of fibrous coagulants caused by the fixative used in the former experiment was observed under the electron microscope. The coagulated fibrous basophilia showed to be composed of the electron dense globules and the electron sparse fibrous elements arranged alternatively, though each of them differed from others in the thickness and length. The size of globules was 100 to 300 mμ in diameter and they looked like a pearl necklace or an elongated rosary stringed with a thread. The fibrous parts threading the globules showed a marked difference in both thickness and length, i. e. in some parts the globules appeared to be contacted closely, or in other parts they were threaded with elongated fibrous parts of 50 to 400 mμ in length. The precise observation revealed that some thick necklace-like structures were constructed by the parallel arrangement smaller units contacting with their corresponding parts. Their size was almost the same with the vesicular structures in the cultured cells fixed with osmium vapor appeared in the report of Poter, i. e. endoplasmic reticulum of them seen on fibroblasts or on nerve cells demonstrated by Palay. Observations on the fixed exocrine cells of pancreas, which have the doubly layered thread-like endoplasmic reticulum, revealed not rosary-like elements but a thick fibrous structure which had almost the same thickness with that of endoplasmic reticulum as revealed on the cells fixed with osmium, and yet some of them showed a distinet double layer. Thus it was confirmed that the analytical results obtained from the observations on the fixed cells by the polarizing microscope should give the picture of molecular arrangement of endoplasmic reticulum of living cells