KATHARINE M. HOWELL 104 1 



jury of lymphoid tissue and that lymphocytes were an important factor in anti- 

 tuberculosis defense. When Benjamin and Sluka' exposed rabbits to X-ray before in- 

 jection of beef serum, precipitin was delayed or absent; but if they did not expose to 

 X-ray until four or five days after injection, the antibody curve was unaffected. Von 

 Heinrich' also found that exposure soon after an injection of antigen in guinea pigs 

 modified the anaphylactic reaction. Hektoen^ exposed white rats to X-rays over a peri- 

 od sufficiently long to reduce the leukocytes and to injure the spleen, lymph glands and 

 bone marrow; he then injected sheep corpuscles; the production of hemolysin was re- 

 stricted, a result in harmony with the conception that the organs mentioned are the 

 site of antibody formation. Dogs and rabbits exposed to X-ray at about the time of 

 injection also had a reduced immunity response. Murphy and Sturm, ■^ by exposing 

 animals to X-ray sufficiently long to injure the lymphoid tissue but not the bone 

 marrow, reduced the antibody response. They thought that this result pointed to 

 lymphoid tissue as the site of antibody production rather than to the reticulo-endothe- 

 lial system, since the reduction of antibody was out of proportion to the injury of the 

 reticulo-endothelial cells. 



In 191 1 Selling^ injected benzene into rabbits and discovered that the bone mar- 

 row especially was damaged but that regeneration took place within ten to twenty 

 days. Several years later, Rusk'' found that rabbits injected with benzene before or at 

 the time of antigen inoculation showed diminished lysin for sheep corpuscle and re- 

 duced precipitin for horse serum. Simons and Jones^ injected rabbits with benzene 

 and learned that lysin for dog corpuscles and agglutinin and opsonin were reduced 

 and that the leukocytes, the polymorphonuclear type in particular, were also dimin- 

 ished. Hektoen^ ascertained that suitable doses of benzene injected before antigen 

 reduced the lysin response to sheep corpuscles in rabbits and the lysin response in white 

 rats. Simultaneously there were gross bone-marrow lesions and severe leukopenia. 

 Minute doses of benzene in dogs stimulated the production of lysin instead of in- 

 hibiting it. Apparently benzene, a drug exerting a destructive action on the blood- 

 forming organs, also depressed antibodies, indicating that there might be some corre- 

 lation between the blood-forming organs and the antibody response. Thorium, which 

 affects myeloid cells more than lymphocytes and erythrocytes, reduced precipitins. 

 Mustard gas had little effect on antibody production when it was given after antigen 

 injection; but when it was given a few days prior to the injection, the appearance of 

 lysin, agglutinin, and precipitin was delayed. Radium emanations given before 

 or at the same time that sheep corpuscles were injected into rabbits depressed 

 both lysins and precipitins. With all these substances that affect the cells of the bone 



' Benjamin, E., and Sluka, E.: Wicn. klin. Wchnschr., 21, 311. 1908. 



= von Heinrich, H.: Ccntralbl. f. Bakleriol., I, 70, 421. 1913. 



^Hektoen, L.: /. Infect. Dis., 17, 415. 1915; ibid., 22, 28. 1918; ibid., 27, 23. 1920. 



■i Murphy, J. B., and Sturm, E.: loc. cit. 



5 Selling, L.: Ziegler's Bcilrage, 51, 576. 1911. 



^Rusk, G.: Univ. Calif. Pub. Path., 2, 139. 1914. 



'Simonds, J. P., and Jones, H. M.: /. Med. Research, 33, 197. 1915. 



^Hektoen, L.: J. Infect. Dis., ig,6g. 1916; Hektoen, L., and Corper, H. J.: ibid., 26, t,t,o. 1920; 

 ibid., 31, 305. 1922. 



