A study of lung lobation in a significant number of primate specimens has not yet been available to us from the literature ; therefore it seems worthwhile to report the results of our own study on a series of rhesus monkeys (Pithecus rhesus -Elliot or Macaca mulatta -Miller). This material was supplied by Dr. C. F. De Garis, who received the specimens from Dr. H. A.
Howe, Johns Hopkins Medical School, where they were accumulated from a study of poliomyelitis, supported by the Roosevelt Warm Springs Fund. To the above contributors of material my best thanks are due.
I n 458 rhesus torsos the lungs were examined, usually in situ, and the patterns of lobation on right and left sides were recorded. The material had been embalmed and stored in 6% formalin, and was in excellent condition for examination. The different patterns of lobation fall into five distinct types, one normal, the other four aberrant. Percentage frequency of each type is computed. Comparisons are made with the human lung, but since available statistics on human lobation are limited to special types of anomalies, such comparisons are incomplete. Nothing is known of the age, sex or genetic strains of the rhesus specimens used in the present study.