So striking and unusual was the recent development of a palsy and atrophy of the right deltoid muscle in a patient who had had a prophylactic injection of tetanus antitoxin that it seemed worthy of report. The rarity of such an occurrence in my experience also led to a review of the literature in an effort to learn of the frequency and of the general prognosis in similar cases. Some fifty cases have been reported by French authors. The most complete work which I have found on the subject is that of C. Petit.1 He has collected reports of forty-two cases and briefly gives the history of each case. The most complete bibliography which I have found on the subject is contained in his thesis. REPORT OF CASE L. P., a man, aged 40, Jewish, a tailor, was referred by Dr. Howard L. Prince to the Strong Memorial Hospital,