The New Student's Reference Work/Galls

Galls, deformities produced on plants by insects, fungi and slime-moulds. One species of insect attacks the root, another leaf, flower or stem. Of insects that cause galls may be mentioned gall-flies, certain caterpillars, a few beetles, certain mites and scale-insects. Eggs are laid in the tissues of the growing plant, and generally the galls appear to form after the egg hatches.