I s T K O~ ucrlosPhysiological experiments have dealt with vesical actirity after section of the nerves innervating the organ. W e h a r e discussed bladder function after section of tlie preganglionic parasympathetic fibers, tlie posterior sacral roots, and the postganglionic sympathetic fibers. When the studies were completed, a certain number of the bladders were preserved for macroscopic and microscopic examination. The paper reports the anatomical findings in these specimens. We will attenipt t o show that there a r e characteristic changes in the morphology of the bladder after each of these operations. There is little available information dealing with the changes in smooth muscle after damage to its innervation. Mechanical factors, dependent upon difficulty in function of the organ, have a great part in the resultant aiiatoriiical abnormalities.TTzr sfri4,cticre of t7ie bladder awl isretlrra in (7; normal cat The bladder of the cat is unusual in that it rises freely into the abdomirial cavity where it can easily be palpated.The urethra is from 4 to 10 mi. long depending upon the distension of the bladder. This mobility makes it possible to