Martinengo Cesarescos Liberation of Italy (London, 1895) is to be strongly recommended, and is indeed, for accuracy, fairness and synthesis, as well as for charm of style, one of the very best books on the subject in any language; Bolton Kings History of Italian Unity (2 vols., London, 1899) is bulkier and less satisfactory, but contains a useful bibliography.
As the stele is traced farther upwards it becomes bulkier, as do the successive leaf-bundles which leave it.
It does not at first appear to be the same with the bulkier plants, such as the ordinary green herbs, shrubs or trees, but a study of their earlier development indicates that they do not at the outset differ in any way from the simple undifferentiated forms. Each commences its existence as a simple naked protoplast, in the embroyo-sac or the archegonium, as the case may be.
Physiological and Morphological Di,fferentiation.The first indication of this differentiation in the vegetative body of the plant can be seen not only in the terrestrial green plants which have been particularly referred to, but also in the bulkier seaweeds.
No doubt the primary object of the cell-wall of even the humblest protoplast is protection, and this too is the meaning of the coarser tegumentary structures of a bulkier plant.