PLATE 2 



EXPLANATION OF FIGURES 



3 Spleen graft of adult tissue, growing on the surface of the allantois of a 

 chick embryo. The culture gave merel.y a slight growth. 



4 The same. Graft intensely growing. The tumor-like graft is well provided 

 with vessels. The culture was made on the 7th day of incubation. The graft 

 is fixed on the 18th dav of incubation, being 9 days old. 



