In the present research skin allografts between normal adult newts (Batch I), skin allografts between adult newts, subjected previously to three spleen grafts (every ten days) from the same skin donor (Batch II), skin allografts between adult newts, subjected previously to three spleen grafts (every ten days) from specimens of Mus musculus (Batch III) have been performed. The results have been evaluated comparing the histological patterns of skin allografts (fixed 20 and 40 days after grafting) in the three experimental batches and mainly comparing the extent of their lymphocytic infiltration. Data emerging from the present investigation emphasize, as we have observed in previous researches, that the quickness and intensity of the host's response to the skin grafts are more precocius and grater if the host had been previously submitted to repeated spleen allografts or xenografts. Furthermore, the same data seems that, in adult Triturus cristatus, the reaction to these grafts is aspecific and therefore an immunological memory, similar to that present in higher Vertebrates, is absent.