91 



Jan. 21 rst 1920 -Leucocytes (2.00 p. m.)=í8 800 per 

 nun). 



Jan. 22 nd 1920-Leuco:ytes (12.30 p. ni.)--=n SOq 

 per ram3. 



Jan. 24 rd 1920— Inoculated peritoneally (1.30 p. tn.) 

 with 3 cc. of saline solution v.-itii 2 loopfuls of a 24 hours 

 culture on gelose of B. paratyphi A. 



Feb. 3 rd 1920— Leucocytes (11.00 a. ra.)=13 COO. 



Killed at 1.30 p. m. 



Histological Study— Under a small 

 power the bone-marrow is seen to be 

 richer in cells than the normal organ. 

 The clear spaces that correspond in 

 the latter to fat-cells are in our case 

 vmrecognisable; in their place nume- 

 rous parenchyma cells diffusedly disse- 

 minated are to be seen. 



The blood-capillaries are not dilated 

 and can be recognised without difficulty 

 (under a weak power) betw-een the nu- 

 merous parenchyma-cells. 



Under a strong power one observes 

 that the most numerous cells are mye- 

 locytes and polymorphonuclear leucocy- 

 tes; it is quite common to see foci of 

 myelocytes and round lhe margins of 

 these numerous polymorphonuclear leu- 

 cocytes. Amongst these, it is easy to 

 find megalocaryocytes, almost all of 

 them with 1 or 2 phagocyted leucocytes 

 in their plasma; cells of the haîmoglo- 

 bm-containing series are also found. 



The most remarkable fact, however, 

 of this bone-marrow in marked hyper- 

 plasia is the existence of foci of proli- 

 feration of the reticulum cells, which 

 form structures at first sight similar to 

 lymphoid follicles (Fig. 17, Plate 17). 



The foci are fairly conspicuous, even 

 under a weak power, on account of 

 the absence of granulocytes in them; 

 they are made up of big cells with a nu- 

 cleus round or oval, poor in chromatin, 

 showing 1, to 3 nucleoli, protoplasma 

 slightly basophil (reticulum cells); stai- 

 ning by anilin blue (MALLORY) sliows 

 that these do not contain any connec- 

 tive tissue fibrils; in certain favourable 

 fields one sees that the protoplasm ot 

 these cells has fine, strands of protoplasm 



which go out towards similar ones froni 

 other cells. These cells have phagocytic 

 activity; their protoplasm sometimes 

 holds desiiitegrating granular leucocytes, 

 round granules stained by eosin and 

 sometimes light yellow pigment. In the 

 foci, there occur other cells amongst 

 these; they have a round nucleus, with 

 abundant chromatin and a protoplasm 

 without granulations; some have the 

 morphology of Ij'm.phocytcs. 



When the focus becomes larger, the 

 big cells occupy the central part, imi- 

 tating the germ centre of a lymphoid 

 follicle with its lymphoblasts; the non- 

 granular mononuclear cells and and lym- 

 phocytes, becoming more numerous, oc- 

 cupy the marginal zone; the appearance 

 reminds one of a lymphoid follicle (see 

 Fig. 17, Plate 17). 



The knowledge we have of the re- 

 ticulum cells of hœmatopoielic organs is 

 not yet definite. Some authorities, like 

 DOWNEY and WEIDENREICH, admit 

 the formation of mononuclear leucocy- 

 tes and lymphocytes at the cost of the 

 reticulum of lymphoid organs. 



I do not wish to assert in a categoric 

 way that the foci I described are lym- 

 phoid organs; that would be the subject 

 of another research. What I should 

 like to slate clearly, is the difference 

 between these foci, which are perhaps 

 lymphoid follicles, and the foci of proli- 

 feration of connective tissue cells (fibro- 

 sis) which were met at every moment 

 in this series of rabbits from the 6th 

 day on, and that indicate small haemor- 

 rhagic centres under way of organisation. 



ASKANAZY thinks that under nor- 

 mal conditions the bone-marrow of 

 children contains lymphoid follicles, 

 which SCHRIDDE denies, assuming that 

 this can happen only under pathological 

 conditions. The lymphoid follicles indi- 

 cated by ASKANAZY showed no germ- 

 centres. 



If ia this rabbit, these should be 

 real lymphoid follicles, which I tliink 



