The question about the morphological value of the ovule, has long been the subject of investigation and discussion, but a decisive answer is stil waited for. The first step to be done in order to throw light on this problem, is to determine to which category of organs, shoot, root or leaf, it can be classified as a whole. Especially during the nineteenth century there has been a good deal of disputing about this subject and nearly all morphologists have occupied themselves more or less with this question. Finely their conceptions and opinions settled on three theories, which are to be mentioned later on, but nobody could give such convincing arguments, that one theory was accepted every where.