33 



DEVELOPING RED BLOOD CORPUSCLES. 



48. Smear preparation of red marrow. 

 A drop or red marrow was spread upon a cover-glass as a thin film 

 (§ 121) ; fixed in a saturated solution of mercuric chlorid (§ 26) 

 15 minutes or so, and placed in 67% alcoliol. Rinse off the alcohol 

 with distilled water and stain with .Ehrlich's triacid mixture (§ 125) 

 for 10-15 minutes, rinse with distilled water, dry and mount in 

 balsam. 



In this preparation find (a) marrow cells, medium sized cells 

 with a large nucleus and scanty protoplasm, resembling leucocytes 

 somewhat ; (6) giant cells, with one or many nuclei ; (c) cells with 

 deeply staining nuclei and more or less hemoglobin in the cell body 

 (stained orange), — -erythroblasts ; {d) finally, red blood corpuscles, 

 non-nucleated. Find as many forms of erythroblasts as possible, 

 and compare with the red corpuscles. 



