imml\c)L()c;k:al stluiks on irradiaikd animals 



little or no antibody. Tho rats injcctccl with spleen cells secondarily stimu- 

 lated in vitro dc\clopcd antibody in their serum, and the curve of antibody 



A 8 12 16 20 



Days after injection 



Figure 1. Transfer of immune spleen cells to normal 



recipients: • — • adult rats — whole cells; • • 



week-old rats — whole cells; • • week-old rats — 



controls; •-x-X-* adult rats — controls 



production is essentially similar to the curve seen in the immunologically 

 immature animals. 



The next experiments were designed to show whether the process of 



81.920 - 



1 



2 3 ^ 5 6 7 

 Days after injection 



Figure 2. Transfer of immune spleen cells to sub-lethally 



irradiated recipients: Q O 2-week-old rats — 



control; □--□ 2-week-old rats — whole cell; A — A 

 adult rats — control; • — • adult rats — whole cell 



antibody production could be initiated by normal cells stimulated in vitro, and 

 transferred to X-irradiated recipients. It can be seen {Figure 3) that adult 



238 



