CARACTERISATION DE LA STRUCTURE D'UN PROCESSUS DE CROISSANCE Application h la croissance des cellules pleuridiophores de l'Algue Antithamnion plumula I CHARACTERIZATION OF THE STRUCTURE OF A GROWTH PROCESS Application to the growth of the pleuridiophoral cells of the alga Antithamnion plumula

The analysis of a growth kinetics y(t) is carried out using the generalized logistic model of Richards - Nelder. Two types of processes, termed mono- and multi-logistic, can be distinguished. In a mono4ogistic process, the phenomenon is adequately described by only one logistic function. The growth kinetics is then characterized by the properties of eseh of phases (71 to G4, with boundaries defined by the singular points Fm~x, Vma x and Fmi n (Buis, 1991, 1993). The growth structure (temporal or diachronie structure) is defined by the relative contribution of the various phases to the expression of the total growth (duration, growth amount, in relative values per phase, independently of Ym~0" This temporal distribution of the growth activity is a discretized representation of the 1 Ce travail a 6t6 r6alisd dans le cadre du programme de recherche du Groupe "Physiologic, Phylog6nie et Morphogdn~se des Algues'.