The fact shown above that local application of saline solutions to the peritoneal surfaces of the intestine could call forth not only muscular movements of the intestine, but also an increased secretion, suggested the possibility of experimenting with loops of intestine entirely removed from the body. Loops thus isolated are necessarily placed under new conditions differing entirely from those under which loops normally connected exist. As mentioned in an early chapter, it was stated by Claude Bernard that section of the spinal cord below the phrenic causes active movements to appear in the intestine; and it was later shown by Pflüger that section of the splanchnic nerves has the same effect, and stimulation of the peripheral cut ends caused the movements to cease. It was also noticed by van Braam-Houckgeest that although loops of the intestine normally connected in the body remained at rest when immersed in isotonic NaCl solution, active movements appear in the loops when the splanchnic nerves are cut. Moreau further showed that section of the mesenteric nerves causes a large increase in the fluid secreted into the intestine. I have confirmed these results and have found that loops which are quiet when the abdomen is opened remain quiet when placed in m/6 NaCl solution. If, however, loops have become active in any way, through exposure to the air, or through any stimulation, these movements continue when the loops are placed in the salt solution. In any case section of the cervical cord or of the splanchnic nerves, or clamping of the nerves and bloodvessels supplying the loops, causes a very marked increase in the peristaltic activity of the loops. In studying the behavior of isolated loops removed from the body and placed in various solutions it was therefore necessary to consider the effects produced by the removal itself.