Abstract: | A method using the comparison between the modifications of spleen weight and on spleen smears visible modifications of the distribution into categories of cells which are classified by the mean of their maturation degree, suggested that these both types of modifications are bound. Therefore, the classic cytological study seems to be a really good tool for analysing the effects of this kind of grafting on the haemopoietic organs, the weight modifications of which are difficult to measure. On the other hand, this method allowed us to see that the distribution of the cell population in the weakly enlarged spleens is very different from both distribution of the population in the strongly enlarged spleens and the controls ones ; this heterogeneity of the stimulating effect of the graft asked us the question whether this one could exerce its influence by the mean of two different ways, at least, or by only one. |