Rickets can be recognized at autopsy with great accuracy at its very beginning by means of histologic examination of the skeleton. All clinical methods for determining rickets are inaccurate and much inferior by comparison. The classic study by Schmorl1 of the prevalence of rickets in Dresden, Germany, between the years 1901 and 1908 was based on the examination in consecutive autopsies of 386 children aged between 2 months and 5 years. Schmorl reported that in the third month of life the prevalence was 61 per cent, from the fourth to the eighteenth month 94 to 98 per cent, from the nineteenth month to the beginning of the third year 91 per cent, in the third year 88 per cent and in the fourth year 71 per cent. He did not determine the prevalance after the fourth year, because of the conviction that the disease occurred infrequently after that age.