86 SPECIAL DISEASES OF THE BLOOD 



Bchistocytosis, punctate basophilia and polychromasia are usually 

 marked. The leucocytes are, as a rule, diminished with relative 

 lymphocytosis. The eosinophiles are usually few in number; 

 myelocytes may be present in small numbers. 



The cause of these changes in the blood in many of the cases 

 seems at present to be unknown. Besides what may be called 

 the cryptogenic cases, there are also others with similar changes 

 in the blood but in which the cause is known. Thus pernicious 

 anemia has been observed in cases of certain intestinal parasites 

 (Bothriocephalus, Ankylostoma), syphilis and malaria. Certain 

 gastro-intestinal disturbances have also been considered as im- 

 portant factors in producing this condition. In short, the con- 

 dition known as pernicious anemia in man is one shown to be due 

 to various causes but presenting characteristic changes in the 

 blood and in the blood forming organs. 



percentage of hemoglobin 

 Hb index = — — — ■ — ■ — 



no. of corpuscles 



percentage of red corpuscles = 



5,000, UUU 



Examples: (1). In a case of secondary anemia in man 2,650,000 red cor- 

 puscles and 40% Hb. were found on examination. The color index is 

 2,650,000 40 



40 -; — = — = .75 the color index. (2). In a case of perni- 



5,000,000 53 

 cious anemia 840,000 red corpuscles and 18% Hb were found. 18 -£■ 



840,000 18 

 = = 1.07 the color index. (3). In a case of chlorosis 



5,000,000 16.8 



4,100,000 red corpuscles and 32% Hb were obtained. 32 -e- 



4,100,000 32 



= — = .39 the color index. 



5,000,000 82 



In dogs, Uncinaria is said to produce a pernicious anemia. A 

 disease in horses in France and Switzerland has been called per- 

 nicious anemia; but the condition of the blood differs widely from 

 thai in man. Meier has reported several cases. The changes in 

 the blood are: The presence of many microcytes, poikilocytosis, 

 polychromasia, megalocytes in some cases, usually no erythro- 



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