The longer a damaged nerve is left unrepaired the less is the chance of there being a satisfactory end result. Primary suture is of course desirable, but under wartime conditions it is rarely possible. Even though it has been found that some time, as measured in weeks, or even in a few months, can lapse before the end result is effected in a measurable degree, it seems desirable to keep the time element to a minimum; this has been done during the past two and one-half years.1 The decision whether surgical intervention is necessary during this early period is difficult to make, and a thorough knowledge of the physiology of the nerve and of the clinical manifestations of disordered function is of paramount importance. Various features of this problem will be dealt with in later communications, but briefly they are those set down by Tinel years ago.2
Recently,