MODIFICATION OF RUNT DISEASE 



363 



the impending effects of runt disease in every case. Nevertheless, 

 of 28 animals treated in this fashion 19 developed distinctly better 

 than untreated controls, with those that died doing so at an 



16 



12 



'10 



Q 6 



O 



OQ 



THREE DAY CELL INJECTION 



C57 spleen cells ^^^ 

 sens, to DBA ^ 



Normal 



C57 spleen 



cells 



Second IV inj. (C57 BL/6 spleen cells) 



4 6 8 10 12 14 16 18 20 24 

 DAYS OF LIFE 



28 



32 



36 



40 



Fig. 10. Mean weight-gain curves of three litters of newborn 

 C57BL/6 mice all of which received more than 10 million DBA/i 

 spleen cells at birth. On the third day of Hfe four animals received 

 an intravenous injection of about 15 miUion C57BL/6 spleen 

 cells from adult donors which had previously rejected DBA/i 

 skin grafts. The remaining five animals received a similar injection 

 of normal adult C57BL/6 spleen cells on the same day. The former 

 animals subsequently developed almost normally. The latter 

 showed considerable delay before eventually reaching normal 

 size. Controls from all htters which did not receive the second 

 injection died of runt disease. 



average age of 3 5 days. Nine survived for over a hundred days 

 and nine died promptly as though unaffected by the second cell 

 injection. DBA/i skin grafts applied to the long-term survivors 

 were rejected normally. An example of a htter in which a second 



