Fingering and Branching Patterns by Bacteria
At first the bacteria grow densely outwards. However, the agar has been deliberately made so that there is an insufficient concentration of nutrients for the bacteria to feed as rapidly as they grow.
Can you relate the nutrients in the agar to a quantity in the metal deposition experiment?
Do you see a similarity to the fingers formed by the bacteria and the fingers you observed in the liquid fingering experiment?
What is your image of how the bacteria are behaving?
Many of these bacteria experiments are done using Bacillus subtilis or Escherichia coli.