CONTACT CEPTORS 89 



Rubbing, dragging, pulling upon or tearing the 

 parietal peritoneum caused a lowered blood-pressure, 

 but the same injury inflicted upon tissues behind 

 the peritoneum caused no marked change in blood- 

 pressure or respiration. In our researches the liver 

 was crushed and cut, the cystic duct was dilated, 

 the kidneys were cut, crushed and contused, the 

 spleen was excised all these operations being per- 

 formed without any appreciable effect upon blood- 

 pressure or respiration, except when, by chance, in 

 the process, contact was made with the peritoneal 

 covering. While gentle handling of the urinary blad- 

 der, the uterus and tubes caused little change, 

 specific injury, such as cutting, compressing and 

 overdistending the bladder, the contusion, incision 

 and rough manipulation of the uterus and tubes 

 caused a rise in blood-pressure, which was especially 

 marked when the full bladder was compressed, or when 

 the uterus was roughly manipulated. Experiments 

 upon the deeper tissues in the retroperitoneal space 

 revealed the fact that the back and spine are almost 

 as devoid of contact ceptors as are the brain, lungs and 

 heart. Injury of the deep fascia, of the muscles or 

 bones of the back caused but little effect on blood- 

 pressure. 



Now what is the meaning of this unequal distribu- 

 tion of contact ceptors ? Our experiments have proved 

 that the greatest number of contact ceptors are im- 

 planted upon the front surfaces and the extremities ; 

 that on the back there are few contact ceptors, while 

 they are almost or entirely lacking in protected areas. 

 The explanation is indicated by the type of trauma 



