IMMUNOLOGICAL COMPETENCE OF SMALL LYMPHOCYTES 247 



and control animals remained conspicuous. Although the 

 majority of experimental mice died of acute runt disease at two to 



22 



20 



18- 



16 



< 



O 



H 12 



I 



uj 10 



5 



2- 



— ° — EXP (RUNT) WEIGHTS 

 CONTROL (NORMAL) WEIGHTS 



10 



15 20 25 30 35 



AGE OF ANIMALS IN DAYS 



40 



45 



50 



Fig. 3. Weight-gain curves for normal A/Jax mice and for A/Jax mice that 

 received 0-9-1 -5 milUon adult C57BL/6 small lymphocytes via the heart 

 during the day of birth. Mean weights with standard errors are given for 64 

 normal mice and for 107 experimental mice, representing a total of 433 and 

 542 individual weights, respectively. 



three weeks of age (MST = 16*4 days), the weight-gain assay 

 continues to reveal the effects of graft-against-host reactions in 

 survivors up to 35 days of age (cf. Fig. 3). Thus the weight-gain 



