IN THE 1951 literature are numerous interesting articles, some of which must have required much time and work in their preparation. Reviewer's notes will appear in brackets.
ANATOMY
Schwartz1 (Halifax, Nova Scotia) became interested in the influence of heredity on the type of pneumatization in mastoids when he found three persons in one family who had sclerotic mastoids. He x-rayed 25 pairs of identical twins and found their cellular development similar. Seven patients who had had otitis media during infancy were studied, and five had both mastoids well pneumatized, one had diploic mastoids, and one had poor pneumatization. He then x-rayed 13 families, one of them containing 54 members, and recorded the structure types. There were altogether 223 patients x-rayed and studied. He is convinced that heredity is the probable explanation of the different types of bone and the extent of pneumatization present and that Wittmaack's theory is not