On some principles of stelar morphology

In the study of anatomical structures in Vascular Plants different ways may be followed, according to the problems the botanist may have to solve. For the study of the tissues attention will be given to the elements, their relationship and the structure of their wall and contents. But for those, who study the distribution of the tissues in the stem and leaves, these tissues, if the true nature be established, will be choosen as the units, of which the structure is considered to be built up.