Morphological Interpretation of Floral Anatomy

Abstract

IN the recent issue of the New Phytologist¹, Mrs. Agnes Arber, in a paper dealing with the above subject, raises certain points which are of fundamental importance to all plant morphologists. She discusses the use of anatomical evidence in phylo-genetic morphology and comes to conclusions which are directly opposed to one of the well-established doctrines of modern comparative morphology. To the question, “Are we to consider it proven that the vascular bundles are more conservative than the external form, so that vestigial organs may be represented by their bundles, when all external trace of these organs has disappeared”, her answer is that “we have no alternative but to discard the doctrine of the conservatism of the vascular bundles”. Proceeding further, she says, “there seems to be no escape from the conclusion that there is a complete absence of positive evidence for the vestigial survival of vascular tissue after the organ which it supplied has ceased to exist”. She admits that the general nature of the vascular scheme may have a certain systematic value and may serve to some extent as an indicator of trends in race history, but in her opinion there appears to be no basis, say, for the statement of Bower² that “anatomical characters and of the vascular system are apt to tardily follow evolutionary progress and thereafter to persist as vestigia” (italics mine).