Variability of allograft rejection processes in

Cellular aspects of histocompatibility in allografts of the sponge have been studied. Three types of reactions were observed : 1) graft acceptance; 2) non-fusion, that is total absence of adherence between the sponges; 3) separative graft rejection, with strong adherence and fusion, followed by secretion of a dense collagen barrier between the sponges. These results clearly point out the variability of immune reactions in .