1 66 NORMAL AND PATHOLOGICAL BLOOD. 



possibly three or four years. Especially in the anaemia of Dibothrio- 

 cephalus latus do we have a picture of pernicious anaemia. It is 

 supposed to be due to a toxin present in the heads of these tape- worms. 



\ 

 SECONDARY ANEMIAS. 



These are the anaemias which can be definitely traced to some 

 disease not of the haemopoietic system. In some secondary anaemias, 

 as in syphilis, carcinoma and tuberculosis, we have a chlorotic color- 

 index (chloro anaemias). 



In secondary anaemias polychromatophilia, poikilocytosis and 

 punctate basophilia (stippling) may be present. This latter is very 

 marked in lead poisoning, but in certain cases of malarial cachexia it 

 may be equally prominent. The only form of nucleated red cell seen is 

 the normoblast, in very small numbers, or it may not be present, 



Megaloblasts are practically never seen, except in some of the very 

 severe parasitic anaemias, as the broad Russian tape-worm infection. 

 The red cells generally number between 2,000,000 and 4,000,000, thus 

 differentiating chlorosis. The leukocytes are frequently increased to 

 15,000. In the anaemia of splenic anaemia there is a marked leuko- 

 penia. In anaemias from malignant tumors the color-index is usually 

 of the chlorotic type the haemoglobin content of the red cells being 

 more affected than the number. Normoblasts are usually present, and 

 this finding may differentiate gastric cancer from ulcer. In bone 

 marrow metastases megaloblasts may be expected. Myelocytes and 

 so-called tumor cells (large cells with faintly-staining vacuolated 

 nuclei and but little cytoplasm) may also be found. As a rule, there 

 is a moderate leukocytosis in malignant disease. Eosinophiles may be 

 largely increased in sarcoma. 



THE LEUKAEMIAS. 



It is in the leukaemias that we have the greatest increase in the num- 

 ber of white cells. These cases show more or less anaemia, but we may 

 have cases of myelogenous leukaemia showing 250,000 leukocytes per 

 cubic millimeter without particular change in the red cells. The more 

 marked the red-cell change the more severe the condition. 



There are two well-defined types of leukaemia, the lymphatic and the 



