INTRODUCTION
The following experiments were carried out with the purpose of ascertaining the effect of various foods commonly used in infant feeding on the bacterial flora of the intestinal tract.It was necessary to ascertain whether the number and variety of organisms varied in different parts of the intestinal tract. It is well recognized that but a small percentage of the bacteria occurring in the feces are viable. Bacteriologic studies of the feces, therefore, have justly been criticized on the ground that the findings give inaccurate data concerning the flora at other levels. Many workers in the field of the intestinal bacterial flora of infants have claimed that definite characteristic flora occur at certain parts of the intestinal tract. Attention has been called especially to the peculiarities of the duodenal flora.Attention has been directed by many writers to the effect certain foods containing relative high percentages of carbohydrates or