SERIAL TRANSPLANTATION OF HAEMATOPOIETIC TISSUE 



61 



Serial passage of bone-marrow in irradiated isogenic hosts 

 Two sets of experiments were designed to study the effect of successive 

 transfers upon the activity of bone-marrow. In the first, C3H marrow 

 (2-6 X 106 cells) was serially passaged into five different groups of irradiated 



15 



10 



Leucocytes/mm 



R 



Control 



,--o 



A 



7 14 



28 



xlO^ 



Control 



Mononuclears/mm 



K 



xlO 



10 



ft Polymorphs /mm 



,/3 



O' 



jy' 



7 



XT' 



<2 Control / 



^^4 



^1 — •- 



14 



28 



7 14 21 28 



Time post -irradiation (days) 



Fig. 1. Peripheral blood analysis of C3H mice before and after exposure to 650 r total-body 

 irradiation, showing the effect of an injection of 5x 10^ isogenic bone-marrow cells given 24 

 hours after irradiation. 



_0_©— Irradiated; — O — O — Irradiated, given bone-marrow. 



