4. Fibrin. Appears as a meshwork of very 

 delicate fibrils in the thicker parts of the film. 



ABNORMAL CELLS AND CONDITIONS 



Normoblast. A nucleated red cell about the size 

 of a normocyte (Fig. i). Two forms occur (a) young 

 forms with the nucleus having its chromatin radially 

 arranged (radkerri) staining more deeply than that of 

 any leucocyte and with a narrow rim of protoplasm. 

 (b) Older forms with dense nucleus and with broader 

 protoplasm. The protoplasm may shew polychromasia 

 (vide below) or basophilia, or both together. 



Fig. i 



Megaloblast. A nucleated red cell of abnormal 

 size (Fig. i). The network of the nucleus is more 

 delicate and stains less deeply than that of any leucocyte. 

 The protoplasm may be very polychromatic so that its 

 resemblance to a leucocyte is then considerable. 

 Basophilia also may be present. 



Pyknosis. The condition of the nucleus in which 

 instead of shewing a network, it appears quite structure- 

 less and stains more deeply than usual. Probably it is 

 an indication of degeneration. This condition may be 

 seen in the two previous erythroblasts. 



Karyorhexis. The condition in which the pyknotic 

 nucleus of nucleated red cells has broken up into 



