valued stochastic process, Poisson point process, iteration/nesting of tessellations, stability of distributions MSC (2010) 60D05, 60G55A tessellation-valued process is considered, the random states of which are planar random homogeneous tessellations stable under iteration (STIT). It can be interpreted as a process of subsequent division of cells by random chords. These chords, referred to as I-segments, have a length and a birth time. In the present paper the joint distribution of the length and the birth time of the typical I-segment for isotropic STIT tessellations is given. Furthermore, later occurring chords have their endpoints in the relative interior of an I-segment and thus generate a node of the tessellation. The distribution of the number of nodes in the relative interior of the typical I-segment is studied.