Arrested development

"1835–1836, Benjamin Phillips, "Bladder, Abnormal Anatomy", in Robert Bentley Todd (ed.), The Cyclopædia of Anatomy and Physiology, Volume I (A–DEA), Longman, Brown, Green, Longmans, & Roberts, page 390, There are upon record a certain number of cases in which two or more urinary bladders are said to have existed. Of these some appear to me to have been cases in which the plurality was maintained merely because the organ was divided into compartments, either as a consequence of arrested development or of the formation of pouches, by the protrusion, or hernia of the mucous membrane of the organ."