DIAGNOSTIC APPLICATIONS OF THE BLOOD-COUNT 275 



mon in advanced stages of the disease, but the diagnosis ought 

 to have been made before their appearance. 



The diagnosis from secondary ancemia rests on the high 

 colour-index, the leucopenia, lymphocytosis, nucleated cor- 

 puscles and megalocytes, and is usually easy. Anaemia asso- 

 ciated with intestinal parasites may resemble idiopathic per- 

 nicious anaemia in every respect except in that the former is 

 accompanied by eosinophilia. In pernicious anaemia the 

 eosinophiles are usually low, and if they exceed 4 per cent, the 

 faeces should be searched for the ova of parasites (especially 

 ankylostoma, bothriocephalus and oxyuris). The anaemia of 

 carcinoma of the stomach and other gastric diseases may 

 closely resemble pernicious anaemia, but in most cases there is 

 a high leucocyte count, with increase of polynuclears and 

 diminution of lymphocytes. 



CHLOROSIS. Here there is a moderate reduction of the red 

 corpuscles and a great reduction of the haemoglobin; the 

 colour-index falls, therefore, and 0-5 may be taken as an aver- 

 age, though much lower figures occur. The corpuscles are 

 pale, but abnormal forms are rare. Normoblasts are very 

 rare, but when they occur usually herald a rapid improve- 

 ment. The leucocytes are normal in numbers, or there may 

 be leucopenia. 



It may be confounded with various forms of secondary 

 anaemia, but in them the colour-index is usually higher, and 

 the leucocytes, especially the polynuclears, tend to be in- 

 creased. 



MYELOGENOUS LEUCOCYTH^EMIA (" spleno-medullary "). 

 There is an enormous increase in leucocytes, which in an aver- 

 age case may amount to 400,000. All varieties of leucocytes 

 are increased in absolute numbers, but the increase mainly 

 affects the polynuclears and the eosinophiles; the lymphocytes 

 are relatively so scanty that they may be difficult to find. In 

 addition, there are abnormal cells : eosinophile myelocytes and 

 large cells with basophile granulations, cells occurring in 

 practically no other disease, and both Ehrlich's and Cornil's 

 myelocytes. 



There is usually anaemia of the secondary type, and normo- 

 blasts are numerous. 



The whole picture is most characteristic, and can hardly be 

 mistaken for anything else. 



