Circulation of Antigen in the Blood. 



37 



the muscular wall and not by the skin. The relaxation occurs 

 when fluid flows in at pressures of only two or three centimeters 

 of salt solution, and a contraction occurs when fluid is flowing out 

 of the stomach. 



The active contraction or relaxation of the rectus abdominis 

 in response to changes of volume of the stomach or changes in 

 volume of intra-peritoneal fluid ceased on section of the dorsal 

 root fibers of the spinal nerves supplying the muscle, and after 

 transection of the spinal cord at the level of the lower cervical 

 roots. Some change in the position of the writing point of the 

 muscle lever occurred when the stomach was distended after each 

 of these procedures, and even a few minutes after death, but the 

 magnitude of the changes was much less than when the central 

 nervous system and the afferent channels were intact. Bilateral 

 vagotomy had no marked effect on the response of the muscle. 



We regard the change in length of the rectus abdominis as a 

 necessary result of the operation of a mechanism for maintaining 

 the relative constancy of intra-abdominal pressure. Without such 

 a compensatory change in length of the abdominal muscles, 

 troublesome circulatory and visceral disturbances would arise 

 when a change in the volume of the abdominal contents occurred. 

 Food could not enter the stomach at such low pressures as have 

 been reported without a corresponding change in the abdominal 

 volume. 



24 (1202) 



A simple method of detecting the circulation of antigen in the 

 blood. (PreUminary note.) 



By J. Bronfenbrenner and M. J. Schlesinger. 



[From the Research Laboratories of the Western Pennsylvania 

 Hospital, Pittsburgh, Penna.] 



Experience with different immunity reactions has brought 

 in the last few years a realization of very important limitations of 

 their usefulness. It is generally conceded that it is impossible 

 by means of immunity reactions to differentiate between actual 

 infection and the state of immunity following it. This difficulty 



