96 



Fig. 5 — Bone-marrow after 54 hours 

 of immunisation (rabbit 212). 



Megaloi'aryocytes with regressive 

 changes (cf. text). 



Plate 20. 



Fig. S — Bone-marrow at the end the 

 3rd daij of immunisation (rabbit 

 215). 



Inteuse proliferation of myelocytes, 

 forming small groups of 3 or 4 

 cells. Diffuse infiltration of 

 Ij^mphocytes. Complete disappe- 

 arance of fat-contents of fat- 

 cells. 



Fig. 9 — Bone-marrow at the end of 

 the 3rd daij of immunisation 

 (rabbit 216.) 



Foci of polymorphonuclear leucocy- 

 tes; many of them superposed 

 on one point show a pyknotic 

 nucleus and other ones are in 

 compleie désintégration (a small 

 infarct). 



Fig. 10 — Bone-marrow at the end of 

 the 3rd dag of immunisation 

 (rabbit 216). 



Increase in number oT fixed connec- 

 á tive tissue cells which whicli are 



seen 10-15 at a time placed side 

 by side and in rows. 



Piale -1. 



Fig. 9 — Bone-marrow al the end of 

 ; the Srd day of immunisation 



t ^ \, (rabbit 150). 



Marked congestion (compai'e with 

 Fig, 1, Plate 18). Parenchyma- 

 cells, although less numerous 

 than in normal marrow, are 

 more numerous than in the first 

 24 hours of immunisation, (com- 

 pare with Fig. 3, Plate 19). 



Fig. 10 — Bone-marrow at the end of 

 the 3rd dag of immunisation 

 (rabbit 150). 



Foci of regeneration of hpemoglobin- 

 containing elements [perivas- 

 cular foci of erythro])lasts (nor- 

 moblasts) ]. 



Fig. 11 — The same section as in fi- 

 gure 9 seen under a higher po- 

 wer. 



The most abmidant parenchyma- 

 cells are myelocytes. 



Plate 22. 



Fig. 12 — Bone-marrow at the end of 

 the 5th day of immunisation 

 (rabbit 367). 



Hyperplasia of paienchyma-cells, of 

 which the most numerous are 

 polymorphonuclear leucocytes. 

 In the fat-ceils can be observed 

 regeneration of fat-contents. Oe- 

 dema of reticulum largely rea- 

 bsorbed. 



Fig. 13 — Bone-marrow at the end of 

 the 1th day of immunisation 

 (rabbit 218). 



Pronounced congestion and grouping 

 of parenchyma-ceils roimd blood- 

 vessels. 



