200 NORMAL AND PATHOLOGICAL BLOOD 



about the leukocytes. Microcytes may be present, and very occasion- 

 ally a normoblast. Macrocytes and megaloblasts are always absent. 

 Blood of chlorotics is very pale and very fluid and coagulates rapidly, 

 hence frequency of thrombosis. 



Spleen, liver, and lymph glands as a rule normal. 



Simple Primary Anaemia. This condition is not recognized by many authors, 

 but is a convenient term under which to group anaemias which are neither chlorosis 

 nor pernicious anaemia and for which no assignable cause can be designated. It 

 is a secondary anaemia without a cause. In it color index is about normal, there 

 is no change in the leukocytes and cases go on to recovery. 



Pernicious Anaemia. In pernicious anaemia we obtain a very 

 fluid, but normally colored drop of blood upon puncture. The yellow 



FIG. 55. Pernicious anaemia. M.m, Megaloblasts; n, normoblast; s, stippling 

 (punctate basophilia). (Cabot.) 



marrow of the long bones is transformed into a soft, bright red lymphoid 

 tissue, smears from which show great numbers of megaloblasts. Areas 

 of fatty degeneration are characteristic, especially the tiger-lily spots 

 in the heart muscle. Iron-containing pigment (hemosiderin) is found 

 in the liver, spleen, and kidneys. Areas of degeneration in the spinal 

 cord may account for nervous symptoms. The red cells frequently 

 fall below 2,000,000 with patients going about. Cases have been re- 

 ported with counts under 200,000. The color index is high. Megalo- 

 blasts are the most characteristic qualitative change in the red cells. 

 Megaloblastic crises may at certain times show enormous numbers 

 of megaloblasts. Cases often present remissions in which no megalo- 

 blasts can be found. In such cases the presence of many macrocytes 



