Online research in philosophy

A determined division wall positioning in each plant cell with respect to the last formed division wall leads to autoreproductive configurations which can simulate plant-like meristems as such with 2/5 phyllotactic patterns. L-map systems are used to generate the corresponding topological wall nets. But in these patterns cells are not six-sided as mostly found in layers. It is shown that wall staggering cannot be a determinate device of the cell itself, nor a randomized dissociation of the cross walls, but results (...) from a physical control with interaction between adjacent cells. It is independent of the cellular program responsible for the appearance of patterns like 2/5 phyllotaxis which is of a pentameric nature. (shrink)

Data from experiments on Erica × darleyensis and from related observations (Viémont and Beaujard, 1983) are taken for a critical analysis of the proposed model of morphogenetic phenomena. The criteria for judging the coherence of the constructions proposed in plant morphology are based on mathematical constructions deduced from Petri nets, especially elementary nets.

Topological developmental models with local (position of internodes) and global (branch lengths) characteristics are proposed to investigate the relationships between fundamental branching patterns of plants such as acrotony, mesotony, and basitony, including the coincidence of different patterns on the same plant. Modification of the basic acrotony during the development by means of, (1) the final expected main axis length results in either basitony or an extension of acrotony over a shortened main axis, (2) the final expected lateral branch length yields (...) either lateral unlimited sympodial branching or the absence of proximal branches. Combinations of these schemes can have variable quantitative expressions on main and lateral axes.As applications, progressive morphological changes introduced by monotonic variations of parameter values give an insight into the relationships between determinate and indeterminate growth, using Lycopersicon as an example. - A theoretical framework is proposed as a possible aid for formalizing plant typology. (shrink)