We present two-cell correlation functions ml(n), which give the average number of t-sided cells adjacent to n-sided ones, obtained experimentally from vegetable tissues and through a numerical simulation that includes mitosis of biological-tissue growth. The correlation functions are not always linear in n, but the Aboav-Weaire law is obeyed, indicating that it is valid for biological tissues and that recent arguments applied to purely topological models are not valid for all natural systems.
Physical Review. E, Statistical physics, plasmas, fluids and related interdisciplinary topics. New York. Vol. 47, n. 5 (May 1993), p. 3712-3716