Bøger i Protoplasmatologia Cell Biology Monographs serien

There is, therefore, still an unmistakable tendency to think of chromosomes in terms of the discrete threads of cell division and, in keeping with this conception, the chromosome cycle is gen erally considered in relation to the microscopically visible changes in morphology which occur during the mechanically active phases of mitosis and meiosis.

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.

If like is to beget like, however, any genetic change which occurs during development must be undone, or else germinal units preserved from change must be set aside. As far as is known, genetic changes, even those involving only quantity or relative amounts, are reversible to only a very limited extent so that a change once done cannot be undone.

obvious properties, its structure, composition, electrical properties, me chanical properties, and most particularly, its permeability properties.

The field of nucleic acids has grown to such a tremendeous size that it is impossible to include all publications concerning the chemistry and biological role of nucleic acids in an article of the length presented in this "Volume.

Introduction When the study of heredity and variation first came to be treated as a scientific subject-and this, one must remember, was only just over a hundred years ago-there was an unfortunate separation between the disciplines of cytology and experimental breeding.