[Sleen enhancement reactions in chick embryo after spleen homografting: autohistoradiography after labeling of graft with tritiated thymidine].

The use as a graft involving an embryonic spleen enhancement of the spleen of an embryo previously grafted (with adult spleen) allowed a very high labelling (3H-thymidine) of the graft and therefore the study of ingrafted cells behaviour: a) on the chorioallantois membrane, b) on the host spleen. In the last case, only a very little number of labelled cells was observed and the whole results confirm the hypothesis of an active participation of the embryo in the case of such an haemopoietic spleen reaction.