It is also possible that contractile vacuoles originate by some form of phase separation not yet understood and possibly involving the contractile properties of proteins, and' it is possible that this process continues to operate in the walls of the vacuoles or feeder canals. This secretory process may be the function of that part of the vacuolar apparatus which blackens on impregnation with osmic acid, and which seems to possess some degree of permanence from vacuole to vacuole and in some cases from parent to daughter cell. Remarkably little is known about the mechanism of systole. General...

Since the publication of my monograph "Die submikroskopische Struktur des Cytoplasm as" Protoplasmatologia III A12 (1955)], science has increased our knowledge on this cell constituent in an amazing way. At that time, cytoplasm was still considered as an amorphous colloid with an amicroscopic structure capable of sol/gel transformations. Meanwhile, within the past 18 years, ultrastructure research and molecular biology have shown that it consists of structured organelles, thereby revolutionizing our concept of the cytoplasm. There is an ontogeny of these organelles which deals with their...