The nodules on the roots of leguminous plants are induced by the presence of a minute organism now known to do no injury to the plant.
An acre used to yield on an average 300 tons of phosphatic nodules, value £750.
Nodules due to eel-worms (Nematodes) are produced on numerous classes of plants, and frequently result in great losses-e.g.
The term coprolites has been made to include all kinds of phosphatic nodules employed as manures, such, for example, as those obtained from the Coralline and the Red Crag of Suffolk.