THE BONE-MARROW. 



209 



of the bone-marrow (see below). In certain pathologic conditions, 

 nucleated red blood-cells are found in the circulation. 



3. Cells with Eosinophile Granules. In the red bone-marrow 

 are found numerous eosinophile (acidophile) cells, some with round 

 or oval nuclei (mononuclear eosinophile cells), others with horse- 

 shoe-shaped nuclei (transitional eosinophile cells), and still others 

 with polymorphous nuclei. The latter, which are the most numer- 

 ous, are no doubt the mature cells, and are identical with those 

 elements of the blood having the same structure. 



Fig. 168. From a section through human red bone-marrow ; X 680. Technic 

 No. 216 : a,f, Normoblasts ; b, reticulum ; c, mitosis in giant cell ; d, giant cell ; e, h, 

 myelocytes ; g t mitosis ; ?', space containing fat-cells. 



4. Cells u>ith basophilic granules. In the bone-marrow are found 

 mononuclear cells in which basophile granules may be differentiated 

 with special reagents. 



5. The various forms of leucocytes and the lymphocytes found in 

 blood and lymph. 



6. The giant cells (myeloplaxes), which are situated in the center 

 of the marrow, and contain simple or polymorphous nuclei, or 

 lie adjacent to the bone in the form of osteoclasts, which are, as a 

 rule, polynuclear (compare p. 120). The physiologic significance 

 of the giant cells is still obscure. They probably originate from 

 single leucocytes by an increase in size of the latter, and not, as 

 many assume, from a fusing of several leucocytes. The giant cells 

 are endowed with ameboid movement, and often act as phagocytes 

 (the latter quality is denied them by M. Heidenhain, 94). 



14 



