270 COLLECTED STUDIES IN IMMUNITY. 



In studying the haemolytic action blood-cells were used which had been 

 freed from serum as much as possible. 



The series of tubes was kept in the thermostat at 37 C. for two to three hours 

 and overnight in the refrigerator at 8 C. In the presence of large amounts of 

 organ extracts haemolysis proceeds rapidly; with small amounts it is very slow. 

 The tubes must be frequently shaken while being kept at 37; the result can 

 only be judged of on the following day. 



To begin we sought to gain a general idea of the hsemolytic action 

 of several organ extracts on various species of blood. The extracts 

 of intestine and of stomach of the mouse as well as that of the stomach 

 of guinea-pigs and of the pancreas of oxen always showed a strong 

 hsemolytic action on all species of blood which we examined, 1.0 cc. 

 to 0.5 cc. of the extracts sufficing to completely dissolve 1 cc. 5% 

 blood of rabbit, guinea-pig, mouse, rat, goat, sheep, ox, pig, horse, 

 dog, or goose. The rest of the organ extracts examined, namely 

 guinea-pig intestine, rat intestine, rat stomach, varied in their hremo- 

 lytic property with different bloods, qualitatively as well as quanti- 

 tatively. Extract of guinea-pig spleen dissolved only dog blood and 

 guinea-pig blood ; extract of mouse spleen possessed a feeble haBmoly tic 

 action on guinea-pig blood and pig blood. Extract of guinea-pig 

 adrenals dissolved both the blood species examined in this case, viz., 

 guinea-pig blood and goose blood. We found the extract of spleen, 

 mesenteric lymph nodes, pancreas, stomach, intestine, and adrenals 

 of one dog to be strongly haemolytic for guinea-pig blood, whereas 

 in another case the spleen showed Itself absolutely inert, although 

 the pancreas was strongly haemolytic. This variation in the haBmo- 

 lytic action on various blood-cells has already been noticed by other 

 investigators, and we therefore desire merely to call attention to a 

 point which thus far has not been regarded, namely, that the organ 

 extracts are able to dissolve the blood-cells of the same species and even 

 of the same individual from which they are derived. 



Thus according to our experience emulsions of guinea-pig stomach, 

 spleen, adrenal, kidney, and intestine, of mouse intestine and stomach, 

 of rat intestine and stomach, of ox pancreas, dissolve the red blood- 

 cells of their own species. The relation existing between this action 

 on the blood of the same species and haemolysis of foreign species of 

 blood is shown by the following two experiments. (See Table I.) 



clumps in the organ extracts which before had been free from visible particles. 

 These clumps could be separated by centrifuge, and exhibited a heemolytic 

 action when suspended in salt solution. 



