EXPLANATION OF PLATES 



AH the figures were drawn with the camera lucida at stage level with Zeiss 

 Apochromat 2 mm. oil immersion obj. The compensatory ocular 4 was used 

 for the figure 10, the oc. 6 for the figures 7, 8, 9, 11, 12, 13, 23 and 24, the oc. 8 

 for the figures 15, 16, 17, 18, 19, 21 and 22 and the oc. 12 for the figures 5, 6, 14 and 



20 



ABBREVI.\TIONS 



Art., artery 



Art.c, arterial capillary 

 Erbl., erythroblast 

 Ere, erythrocyte 

 Ere.,'" degenerated erytlirocyte 

 Fbr., fibrous tissue 

 Grbl., granulocytoblast (myelocyte) 

 Grc, granulocyte (granular leucocyte) 

 Grc.,'" degenerated granulocyte 

 Gtc, giant cell 



L.Hbl., lymphoid hemocytoblast, with 

 a denomination — mitosis of the corre- 

 sponding cell 



L.Hbl., " lymphoid hemocytoblast in the 

 stage of its isolation from the mesen- 

 chymal syncytium 



Msc, mesenchymal cells 



Ms. St., mesenchymal syncytium 



S., sinus 



S. L.Hbl., small lymphoid hemocyto- 

 blast 



S.Lmc, small lymphocyte 



I. L.Hbl., intra-vascular lymphoid he- 

 mocytoblast 



E. L.Hbl., extra-vascular lymphoid he- 

 mocytoblast 



PLATE 1 



EXPLANATION OF FIGURES 



1 Slight hypertrophy of the spleen, corresponding to the graft, reproduced 

 on figure 3. Eighteenth day of incubation. 



2 Enormous hypertrophy of the spleen, corresponding to the graft, repro- 

 duced on figure 4. Eighteenth day of incubation. 



310 



