INFLUENCE OF ROEXTGEX RAYS UPON METABOLISM 877 



great change in the leucocytes in the peripheral blood but there was a 

 marked reduction in the production of antibodies hernolytic for red blood 

 corpuscles of the rabbit. 



Morton found that exposure of guinea pigs to x-rays rendered these 

 animals more susceptible to experimental tuberculosis and suggested 

 such preliminary radiation for the routine diagnosis by the guinea pig 

 method. Kessel and Sittenfield, however, believe that after a certain stage 

 radiation tends to prolong the life of a tuberculous guinea pig and to 

 promote healing. Kellert finds that in routine work preliminary radiation 

 does not hasten the diagnosis by rendering guinea pigs more susceptible to 

 tuberculosis but that the increased susceptibility of such animals to sec- 

 ondary invaders and contaminating organisms interferes with the 

 routine work. Corper and Chovey, by subjecting mice to a single non- 

 lethal dose of x-rays or to a single non-fatal injection of tliorium-x, sub- 

 sequently found that these animals showed an increased susceptibility when 

 inoculated with pneumococci (four types) and hemolytic streptococci (hu- 

 man and bovine). 



Russ, Chambers, Scott and Mottram in experimental studies with 

 small doses of x-rays, following the work of Murphy and Morton (a), on 

 the blood of rats in its relation to rat susceptibility in Jensen rat sar- 

 coma find that the natural immunity which these animals have towards 

 inoculation of spontaneous tumors can be broken down by an x-ray ex- 

 posure sufficient to cause the disappearance of the lymphocytes. Prime 

 on the other hand did not succeed in rendering rats naturally immune to 

 the Flexner-Jobling rat carcinoma, more susceptible by reducing the lym- 

 phocytes as advocated by Murphy. Murphy and Taylor have shown that 

 the acquired immunity resulting from the inoculation of blood or other 

 cells into normal animals can be similarly destroyed. The acquired im- 

 munity found in animals in which tumors have disappeared, according 

 to Mottram and Russ, can be broken down only so long as lymphoid cells 

 are reduced in number. Tumor cells from a foreign species which on in- 

 oculation will grow only with great rarity multiply rapidly in an x-rayed 

 animal until such a time as the depleted lymphoid tissues are well 

 advanced in regeneration (Murphy). 



On the other hand Russ, Chambers, Scott and Mottram, and Murphy 

 and Morton (a) have shown that an immune condition can be produced in- 

 stead of destroyed by suitable dose? of x-ray. After the removal of tumors 

 from mice by operation Murphy and Morton(fc) gave small dose of x-rays 

 and found that grafts of the same tumors when inoculated did not grow 

 in twenty-six out of fifty-two mice and that there was no recurrence at 

 the site of operation in forty-one animals. In twenty-nine control mice 

 who were not given small doses of x-rays the grafts grew in twenty-eight 

 and there was local recurrence in fourteen. 



