DIAGNOSTIC APPLICATIONS OF THE BLOOD-COUNT 217 



part that remains is normal. In a very short time, however, fluid 

 IS absorbed from the tissues so as to make up the normal volume, 

 and in consequence the red corpuscles and hsemoglobin fall in the 

 same proportion. With this there is usually a leucocytosis, high 

 figures (20,000 or more) being sometimes reached ; do not forget 

 this m dealing with a blood-count in a patient who has recently 

 had a haemorrhage. As the process of regeneration continues, the 

 improvement shows itself first in an increase of the red corpuscles, 

 so that the colour-index falls slightly (to about 0-9). 



The anaemia from repeated haemorrhages is one of the varieties 

 of secondary anaemia. 



Secondary Anemia. — This term is used for anaemia which is 

 due to any definitely recognised cause — haemorrhage, malnutrition, 

 sepsis, intoxications {e.g., lead-poisoning), etc. — that is to say, it 

 includes all cases of anaemia except those of unknown pathology, 

 such as chlorosis and pernicious anaemia. 



In secondary anaemia there is a reduction of red corpuscles to 

 an extent dependent on the potency and continuance of the cause, 

 and a slightly greater reduction of the haemoglobin, so that the 

 colour- index is lowered. It does not -usually fall below 07, 

 and 0-8 may be taken as a fair average. Anything below this is 

 rarely met with apart from chlorosis. The red corpuscles are 

 usually practically normal in appearance ; normoblasts are rare, 

 and their presence is a good sign. 



The leucocytes, especially the polynuclears, are usually slightly 

 increased, and this is the chief or only means-of distinguishing a 

 secondary anaemia with low colour-index from chlorosis, in which 

 the leucocytes are normal or reduced. 



Pernicious Anemia. — The feature which usually first raises 

 suspicion of pernicious ansmia is the high colour-index. It is 

 usually over i, and, taking the average of a number of cases, 

 it increases in proportion to the amount of reduction of the 

 corpuscles, thus : 



