[Splenomegaly reaction of the chick embryo following chorio-allantoid graft of chicken-spleen fragments].

The spleen enhancement reaction of the chick embryo, following the insertion (grafting or injection procedure) of homologous spleen cells is one of the results of the graft-versus-host reaction (G.V.H. reaction). Irrespective of the usual kinds of G.V.H. reaction measured, it has been proved that the relation between the number of immuno competent cells and the reaction intensity is linear. Our study shows that the relation is not the same when the chorio-allantois membrane grafting procedure is used instead of injection into the veins. However, two facts remain unchanged 1) the minimal amount of spleen cells sufficient to provoke a spleen enhancement is low, 2) there is a link between the number of homologous spleen cells and the rate of spleen enhancement, but in this case it was not shown to be linear. In the light of this, the role played by the chorio-allantois membrane is being debated.