Fibrillation of events in the cambial domains of Tilia cordata Mill.

The cambium and 9 annual growths from a linden stem were studied. Some of the fusiform cell ends changed their contacts-which is shown by the comparison of the cambium layer and terminal parenchyma of the phloem. This means that these ends were active in the period the layers under comparison were formed. The active ends were found in groups numbering a few to ten-odd ends alternating with groups of inactive ends. About 70% of the ends retained their activity for only one year. In the studied areas. in a given year, one direction of migration of the active ends dominated. As a rule, this configuration changed every two years. Along with the change in the configuration of the active ends, the position of the active areas also changed in such a way that after the change of configuration, the areas previously inactive became active. No migration of activity along the borders of the storeys was observed, but only its appearance and disappearance, which was called fibrillation of activity. Fibrillation of activity becomes noticeable when there is a low intensity of events. Because the active areas at a given moment are characterized by one type of configuration of events, the whole studied surface can be seen as a single domain. Fibrillation gives the impression of frequent changes of domain type, these changes, however, are of a different nature than the movement of domain borders found in cambium characterized by a high intensity of events