Electron Microscopic Observation of Plastids and Mitochondria during Pollen Development in Tradescantia paludosa

Changes in the structure of plastids and mitochondria were observed with the electron microscope during the microsporogenesis and pollen development of Tradescantia paludosa. It was found that either organelle develops more or less synchronously and divides simultaneously within certain limited periods. Generation of the organelles is, thus, recognized. The plastids develop from proplastids to amyloplasts in each generation. The mitochondria take characteristic morphology for each generation (Tex-fig. 1). On the contrary to the Golgi body, the plastids and the mitochondria keep their continuity through alteration of generation; namely, at the division periods amyloplasts turn to proplastids by diminution of starch in the case of the plastids, and the meta-morphosis of forms or internal structures takes place in the case of the mito-chondria.