In describing these experiments, which were made some time ago,[60] a word may be said as to the methods employed. The rabbits were anaesthetized with morphine as described before; the abdominal cavity was opened and the bloodvessels supplying the loop selected were carefully tied off. Two pairs of ligatures were then placed around the intestine so that the loop was properly isolated. The intestine was then cut between each pair of ligatures, and the mesentery divided between the bloodvessel ligatures and the intestine. In this way the loop could be taken from the body without injuring it, and without causing the animal to lose more than a drop or two of blood. The loop was then emptied by cutting one ligature and allowing the fluid to drain from that end while it was held up by the ligature of the other end. The open end was then religatured, and the whole loop suspended in the solution to be tested. This was arranged so that both ends of the loop were above the surface of the solution, in order that none of the solution could by any possibility enter the lumen of the loop through the ligatured ends. The beakers containing the solutions were kept in a water bath at 39.5° C. The movements of the loops could in this way be directly watched, and the amount of fluid secreted in a unit of time could be easily measured. If a loop such as has been described above be removed from the intestine of a rabbit and placed in m/8-m/6 NaCl solution at body temperature, active movements at once appear. These are regular and rhythmical, resembling those which set in when the nerves to the intestine are cut in the uninjured animal. If the loop be allowed to lie at the bottom of the solution, it will twist and writhe about in a peculiar worm-like manner. These movements persist in varying intensity for a considerable time, sometimes as long as an hour, usually for 40-45 minutes. They disappear gradually. No attempt was made to obtain a fluid in which the movements could be maintained for a longer time. These movements are probably merely the continuation of those always caused by sectioning the nerves to the loop. The m/6 or m/8 NaCl solution seems to be fairly favorable for their maintenance. That the loop, however, is not dead when the movements in NaCl cease is shown by the fact that it can be caused to exhibit active movements by transferring it to a solution of NaCl containing a small quantity of BaCl_{2}. It is of course not possible to say that the movements which appear when the loop is placed in pure NaCl solution are entirely due to the cutting of the nerves to the loop. It is possible that the NaCl acts as a direct stimulus and causes the movements to continue.