120 NORMAL HISTOLOGY AND ORGANOGRAPHY. 



blood-corpuscles. They are supposed to play an im- 

 portant role in the coagulation of blood. As soon 



r 



Fig. 84. Ehrlich's leucocytic granules (from preparations of 

 H. F. Miiller): a, Acidophile or eosinophile granules, relatively large 

 and regularly distributed; e, neutrophile granules; /?, amphophile 

 granules, few in number and irregularly distributed; ?, mast cells with 

 granules of various sizes; d, basophile granules; (a, o, and e, from the 

 normal blood; ?-, from human leukemic blood; /?, from the blood of 

 guinea-pig) (Bohm and Davidoff). 



as blood is shed most of them disappear, unless spe- 

 cial precaution is made to preserve them. They may 

 be preserved by pricking the finger through a drop 

 of osmic acid. Their number per cubic millimeter 

 is from 200,000 to 600,000. 



According to Wright's investigations, these plate- 

 lets represent detached portions of giant cells found 

 in bone-marrow or in the spleen. Schafer regards 

 them as minute cells, while others think of them as 

 fragments of red or white corpuscles. 



Hemin Crystals (Teichman's crystals). These 

 come from the hemoglobin of the blood, and when 

 found are always a positive evidence of blood. The 

 crystals can be obtained from clotted blood, no mat- 



