268 COLLECTED STUDIES IX IMMUNITY. 



by its behavior toward heat, completely losing its action on being 

 heated to 56 C. for three-quarters of an hour. 



Observations in this same direction have been made by Shibayama l 

 and Klein, 2 and a comprehensive study by Tarassevitsch 3 has recently 

 appeared from Metchnikoff's laboratory. 



Shibayama, working in Kitasoto's laboratory, studied the action 

 of extracts of guinea-pig organs on dog blood and obtained haemolysis 

 with those of spleen and lymph glands, but not with those of bone 

 marrow and other organs. Without further analysis he classes as 

 identical the namely tic substances of the organs and the specific 

 hoomolysins which appear in the serum after immunization with dog 

 blood-cells. This leads him to the following conclusion: "From the 

 facts mentioned it can readily be seen that the hsemolytic side-chains 

 of the guinea-pig are already physiologically present in the spleen and 

 lymph-glands and that the injection of dog blood aids their hyper- 

 production." 



Klein prepared the organ extracts by crushing them with quartz 

 gravel, then mixing with an equal amount of physiological salt solu- 

 tion and filtering in the cold. The only constant effect was the 

 hsemolytic action of the extract of pancreas; in a few cases the ex- 

 tract of kidney and of intestinal mucosa also dissolved the red blood- 

 cells. 



Metchnikoff's experiments were continued in his laboratory by 

 Tarassevitsch, who studied principally the organs of guinea-pigs, 

 rabbits, and dogs. Corresponding to Metchnikoff's first experiments, 

 he tested the hsemolytic action mostly on avian blood-cells, but also 

 on those of mammals. In the guinea-pig, in the great majority of 

 cases, he found the extracts of omen turn, mesenteric lymph-glands, 

 and spleen to be hsemolytic. Besides this pancreas extract and in 

 many cases salivary gland extract were hsemolytic. In general the 

 hsemolytic action of the organ extracts of rabbits is weaker than that 

 from the organs of guinea-pigs. Omentum, spleen, and mesenteric 

 glands frequently were hsemolytic; the salivary glands acted feebly; 

 bone marrow, liver, and thymus were not hsemolytic. According to 

 Tarasseritxcli, therefore, only the macrophagic organs and the digest re 

 glands possess a Jurmolytic action. 



1 Shibayama, C'entralblatt f. Bact., Vol. 30, 1901, No. 21. 

 ' Klein, K. k. Ges. der Aerzte in Wien, Sitzung von Dec. 20, 1901, reported 

 in Wiener klin. Woehenschr. 1901, No. 52. 



3 Tarassevitsch, Sur les Cytases, Annal. de 1'Inst. Past. 1902. 



