THE LTSINS. 129 



supposition that the intermediary body exists in the dog serum, while 

 the complement is furnished by the serum of the guinea-pig ; in this 

 case the complement is furnished by the serum of the animal whose 

 corpuscles are dissolved. It is probable that in various sera both the 

 intermediary bodies and the complements differ, and it is not always 

 possible to restore the hemolytic action of a serum, which has been 

 heated, by the addition of a complement. For instance, eel serum 

 is hemolytic to the blood of most mammals ; it loses its hemolytic 

 action when heated for fifteen minutes to 54°, and so far no method 

 of restoring its activity has been discovered. 



In a third communication Ehrlich and Morgenroth ' carried out 

 their immunization experiments in a wholly different way. 920 c.c. 

 of the mixed blood from three goats (Nos. 1, 2 and 3), diluted with 

 750 c.c. of water, was injected into the abdominal cavity of a large 

 goat (A) at one time. From the second day on small quantities of 

 the blood were taken from this animal and the hemolytic action of 

 the serum tested. The first experiment showed that this serum 

 possessed slight hemolytic effect on the corpuscles of other goats, 

 and on the seventh day it reached its maximum. At this time 0.3 

 c.c. of the serum completely dissolved the corpuscles in one c.c. of a 

 five per cent, dilution of goat No. 4. It was tested upon nine goats 

 and it was found that the susceptibility of the erythrocytes of these 

 animals to the serum varied somewhat. The serum of the treated 

 animal was found to be without effect upon its own corpuscles. 

 Ehrlich suggests that the hemolj^ic action of the blood serum of one 

 animal upon the corpuscles of another species be designated as 

 " heterolysis," and the active agent or agents in the hemolytic 

 serum in this case be termed " heterolysins," while the hemolytic 

 action of the serum of one species on the corpuscles of another indi- 

 vidual of the same species be designated as "isolysis," and the 

 active agents as " isolysins." If a serum should be found which 

 dissolves the corpuscles of the individual from which the serum has 

 been obtained, the process would be designated " autolysis," and the 

 active agents as " autolysins." No one has as yet discovered an 

 autolysin, although the possibility of the existence of such a sub- 

 stance cannot be denied. It is possible that certain diseased con- 

 ditions, which we have designated as auto-intoxications, may be 

 caused in this way. 



Ehrlich designates the haptophorous group in the corpuscle, or 

 the side-chain in the corpuscle which combines with the intermediary 

 body, as the " receptor." He supposes that it is by the action of these 

 receptors that hemolysins, and other toxins as well, combine with 

 and destroy the cells of the body. He illustrates his views of the 

 relationship between the cell, the intermediary body and the comple- 

 ment, also the action of other toxins, by the accompanying drawing. 

 1 Berliner Hin. Wochenachrifl, 1900, 453. 

 9 



