Thoracic duct fistulae in dogs created under local anesthesia and draining continuously from two to eight days have been utilized for the study of lymphocyte output. Too few observations have been made for them to be statistically significant. It is realized that after several days of fistula drainage, factors other than the simple loss of lymphocytes through the thoracic duct fistula may have influenced the lymphocyte output. The necessity for taking into consideration the many factors which may influence lymphocyte output in the evaluation of the effect of any single factor is emphasized.
ACKNOWLEDGMENT The authors would like to express their appreciation to Dr. John H. Gibbon, Jr. and to Dr. Cecil K. Drinker for their helpful suggestions in the accomplishment of this work.