PRIMARY ANAEMIAS. 313 



When the red blood-corpuscles are reduced in number they 

 are usually more or less altered in shape, according to the 

 degree of the oligocythsemia. Poikilocytes, microcytes, and 

 polychromatophiles are frequently present, and, when the con- 

 dition is very severe, megalocytes may be quite numerous; 

 nucleated red blood-corpuscles usually normoblasts are 

 sometimes seen. The number and variety of leukocytes are 

 normal in uncomplicated cases. 



The only associated organic lesion which has been noted 

 is a congenital smallness of the heart, bloodvessels, and 

 genital organs. 



Progressive pernicious anaemia is a severe anaemia which has 

 no apparent cause and tends uninterruptedly toward a fatal 

 issue. The number of red blood-corpuscles is reduced to a 

 greater degree than in any other condition, sinking below five 

 hundred thousand per cubic millimetre, even to one hundred 

 and forty-three thousand in one case which has been recorded. 



A characteristic feature is the average increase in size of 

 the red corpuscles. Microcytes may occur, but are not com- 

 mon. Erythroblasts, poikilocytes, and polychromatophiles are 

 frequently noted. The haemoglobin is always reduced, but 

 never to the same extent as the red blood-corpuscles. The 

 leukocytes undergo no important change. 



In some cases it has been possible to assign a cause. 

 Atrophy of the gastro-intestinal mucous membrane and certain 

 intestinal parasites, especially the anchylostoma duodenale, 

 produce a secondary anaemia, often not distinguishable from 

 progressive pernicious anaemia. The anaemia is usually looked 

 upon as resulting from the excessive destruction of blood 

 rather than from its defective formation. The pigmentation 

 of various organs, the jaundice often present, and the excess 

 of coloring-matter in the urine suggest this conception of its 

 nature. 



The various viscera are pale and bloodless, and in a more or 

 less advanced stage of fatty degeneration. 



A simple primary anaemia arising without any apparent 

 cause is not recognized by many writers, yet cases do occur in 

 which the characteristic features of both chlorosis and per- 



