IN THE past, many workers have reported that the urinary bladder is in an atonic state immediately after injury to the spinal cord. Holmes,1 Walker2 and Fearnsides3 observed men with injuries of the spinal cord during the first World War and came to the conclusion that the detrusor muscle was always in a lax condition after injury to the medulla spinalis. More recently it has been stated by Munro and Hahn4 and by Riches5 that there is complete atonicity or flaccidity of the detrusor muscle during the period of spinal "shock" (a condition following transection, contusion, concussion or edema of the spinal cord). Valk6 studied 112 cases of acute injury of the spinal cord during the second World War, and in no case did he observe flaccidity of the detrusor muscle in patients in whom drainage was carried out immediately after the injury. Experimentation