The Gall-Making Diptera of Scotland is a book written by James William Helenus Trail and originally published in 1888. The book is a comprehensive study of the various species of gall-making flies found in Scotland. Gall-making flies are a type of Diptera, which are insects that have two wings and belong to the same order as flies and mosquitoes. The book begins with an introduction to the study of gall-making flies and their importance in the ecosystem...