13 
G. P. No. Cx. Collodion sac containing about 3 c. c. normal horse (No. 15) serum 
placed in peritoneal cavity. 
28 days later, 5 c. c. normal horse (roan) serum, subcutaneously. No symptoms. 
1 day later, sac removed. 
23 days after removal of sac, 5 c. c. normal horse (roan) serum, suhcntaneously. 
Mild symptoms. 
By reference to page 62 it will be seen that guinea pigs ma}^ be sen- 
sitized by injecting horse serum directl}^ into the heart. 
Further work upon the action of the sensitizing substance is in 
progress and will be reported later. 
