  The key feature of a memristor is that the resistance is a function of its
previous resistance, thereby the behaviour of the device is influenced by
changing the way in which potential is applied across it. Ultimately,
information can be encoded on memristors, which can then be used to implement a
number of circuit topologies. Biological substrates have already been shown to
exhibit some memristive properties. It is, therefore, logical that all
biological media will follow this trend to some degree. In this paper we
demonstrate that a range of yet untested specimens exhibit memristive
properties, including mediums such as water and dampened wood shavings on which
we can cultivate biological specimens. We propose that memristance is not a
binary property {0,1}, but rather a continuum on the scale [0,1]. The results
imply that there is great potential for hybrid electronic systems that combine
traditional electronic typologies with naturally occurring specimens.
