A fermenter for growth of a multicellular organism, comprising a vessel defining a fermentation chamber and a space-filling lattice of inoculation points adapted to be located within the chamber. The inoculation points may be formed from wires 3 meeting perpendicularly (Fig. 4) or not quite meeting (Fig. 3) or from barbs (5) on wires (3) or rods (Figs. 5 to 10). The fermenter is suitable for the growth of hairy roots. Disorganisation of organised plant tissue can be attenuated by the removal of disorganisation-promoting compounds from the medium.
