KATHARINE M. HOWELL 1037 



sidered that the bacteria were destroyed by the Hver and that in some way during 

 the period of destruction antibodies were formed possibly by the endothehal phago- 

 cytes. 



Complement fixation antibodies were found by Tsurumi and Kohda' in higher 

 concentration in spleens than in sera, twenty-four hours after rabbits were injected 

 with typhoid bacilli. After forty-eight hours the serum gave strongly positive fix- 

 ation, and later bone marrow and lymph nodes gave slightly positive fixation. Sim- 

 ilar experiments on splenectomized rabbits showed that the complement fixation 

 antibodies appeared earlier in the lymph nodes than in the serum. 



Precipitin was believed by von Dungern^ to be produced by the formed elements. 

 Kraus and Levaditi^ demonstrated precipitin in extracts of omentum after intraper- 

 itoneal injection of horse serum. The serum and extracts of the other organs did not 

 give this reaction. Kraus and Schiffman^ did not obtain precipitin reactions with or- 

 gan extracts after injection of horse serum either intravenously, intraperitoneally, 

 or subcutaneously. They concluded that possibly precipitin was produced by the 

 vascular endothelium rather than by any single organ. Cantacuzene,^ using stronger 

 organ extracts than Kraus and Schiffman, was able to demonstrate precipitin in the 

 extract of spleen within two to three days after injection of horse serum; this pre- 

 cipitin gradually decreased until there was no trace on the seventh day, when precip- 

 itin first appeared in the blood. 



The experiments cited appear to indicate that primarily the spleen and second- 

 arily the lymph nodes, bone marrow, liver, kidney, lung, and omentum are involved 

 in the production of antibody, since it is present in some or all of these organs before 

 it appears in the serum. The fact that the injection of high titre, immune serum does 

 not increase the antibody content of these organs suggests that they produce rather 

 ihan store the antibodies. It seems probable that the formation of antibody may de- 

 pend on some element common to all these organs, such as lymphoid tissue, hemato- 

 poietic tissue, or reticulo-endothelial cells. Many investigators,among them Rath'' and 

 Fodor and Rigler,^ failed to demonstrate antibodies in organ extracts. In most in- 

 stances the tests for antibodies were not made in the first days of immunization. 

 Courmont, cited by Rath,'' found agglutinin higher in the serum of patients who had 

 died from typhoid fever than in bile or extracts of liver or spleen. Here again the ex- 

 aminations were probably not made early in the disease. 



TISSUE CULTURE IMMUNITY 



Shortly after Harrison^ in 1907 and Burrows" in 19 10 succeeded in growing tissues 

 in vitro, Carrel and Ingebrigtsen'" recognized that such living tissue culture offered a 

 'Tsurumi, M., and Kohda, K.: Ztschr.f. Ivnmtnitatsforsch. u. expcr. Thcrap., 19, 519. 1913- 



2 von Dungern: ibid., Orig., 21, 326. 1914. 



3 Kraus, R., and Levaditi, C: Compt. rend, de VAcad. de sc, 138, 865. 1904. 



4 Kraus, R., and Schiffman, J.: Ann. de I'Inst. Pasteiir, 20, 225. 1906. 



5 Cantacuzene, J.: ibid., 22, 54. 1908. ^ Rath, D.: CcnlralU.f. BaklerioL, I, 25, 549. 1899. 



7 Fodor and Rigler: ibid., 23, 930. 1898. 



8 Harrison, R. G.: J. Exper. Zool., 9, 787. 1910. 

 » Burrows, M. T.: J.A.M.A., 55. 2057. 1910. 



"> Carrel, A., and Ingebrigtsen, R.: /. Expcr. Med., 15, 287. 1912. 



