Last week I set up my third (and for the time being, last) experiment with earthworms. This time I give them different levels of CO2 in the air to see if that has an influence on granule production. The species of earthworms I use is Lumbricus terrestris. One of the most common species you’ll find in your average European garden. I order them at a company that sell them for fishing, and who actually get them from Canada, where they have been introduced by Europeans to improve agriculture. In Canada they even have worm vending machines.
In the lab the worms each get their own bag of moist soil ad horse manure (food) and are kept in darkness and at constant temperature. To achieve the different CO2 levels they are then put in so-called gloveboxes through whcih air with a constant CO2 level is pumped.
Two gloveboxes containing 6 bags-of-soil-with-worm.
And now I wait.
Silent witnesses 