Such a culture can be kept forever by successive transplantations onto fresh nutrient agar. The transplantations occur every three to eight weeks. Callus cultures are no cell cultures, since whole tissue associations are cultivated. Though many cells keep their ability to divide, is this not true for all. One reason for this is the aneuploidy of the nuclei and the thus caused unfavourable chromosome constellations.
Coconut milk is liquid endosperm.
In nature does it stimulate the embryo to grow which it supplies at the same time with food. Results yielded from callus cultures showed that its active components stimulate the growth of foreign cells, too. The thus developing callus grows when supplied with yeast extract, coconut milk or old DNA preparations. Freshly prepared DNA has no effect but becomes effective after autoclaving. This led to the conclusion that one of its breakdown products is required for cell growth and division.