they obtained cultures developing in two zones, one near the top and the other near the bottom of the tube, indicating that there are two optima in the oxygen requirement of the organism. This very interesting character of the organism received great attention at their hands, but nevertheless Bang points out that typical development such as he has pictured was not always obtained, a number of factors seeming to cause variation in the position and extent of the developmental zones in these tube cultures. By exhausting the air above the medium in the tube, the growth was made to extend to the surface. In this way they were able to obtain growth of the bacillus on plates, but they did not work out a reliable plate method, preferring to employ the dilution tube cultures for separation in all their work. Bang and Stribolt subsequently examined pieces of placenta from a large number of cases of contagious abortion, and found the bacillus microscopically in practically all cases. Sometimes they were abundant, in other instances very scarce. Most of this material was badly contaminated, yet, from that sent in during the colder season they successfully isolated the bacillus in pure culture in a majority of the cases. In three fetuses the bacillus was found in the intestinal contents in pure culture; in one fetus it was isolated from the blood. Two cows with mummified fetus _in utero_ were examined _post mortem_. These fetuses had been dead 9 months and 5 months respectively but the surrounding exudate still contained the abortion bacillus and pure cultures of it were obtained from each case. Uterine exudate kept in the refrigerator still contained living abortion bacilli after seven months.