222 CLINICAL BACTERIOLOGY AND H^EMATOLOGY 



associated with a low colour-index ; in some cases, however, it 

 may be high, and I have seen if as high as i"8. (2) High 

 leucocytosis, often 50,000 or more, with extraordinary changes in 

 the leucocytes, so that they can hardly be classified on the usual 

 lines ; myelocytes are not uncommon. (3) Striking and profound 

 changes in the red corpuscles, the most important being the 

 presence of numerous normoblasts, many of which show dividing 

 nuclei (Plate VIII., Fig. 8) ; megaloblasts and atypical forms 

 occur, but are less numerous. The non-nucleated red corpuscles 

 show all forms of degeneration, poikilocytes, megalocytes, and 

 microcytes being present, whilst many are affected with granular 

 basophilia (Plate VIII., Fig. 2) or polychromatophilia (Plate VIII., 

 Fig. 3). In severe cases the majority of the red corpuscles may 

 be abnormal, and the appearance of the stained films is very 

 extraordinary. 



The prognosis of these cases is fairly good if proper treatment 

 be adopted — much better than in the primary blood diseases with 

 which they might be confounded. 



Sepsis, Suppuration, and Septicemia. — In most cases of infec- 

 tion with septic bacteria, whether local or general, there is marked 

 leucocytosis, due especially to an increase in the polynuclear 

 leucocytes. For instance, in an ordinary case of appendicitis 

 of average severity we may expect the number of leucocytes to 

 rise gradually to 25,000 or 30,000, about go per cent, being poly- 

 nuclears. At the same time there is usually a moderate fall in 

 the amount of haemoglobin and in the number of red corpuscles. 

 In practice we have to consider three types, in each of which the 

 blood-counts vary. 



I , Very Severe Cases. — Puerperal and other forms of septicaemia, 

 general septic peritonitis due to very virulent bacteria, especially 

 in an enfeebled patient, etc. 



Here there may be but slight leucocytosis, and this, taken in 

 conjunction with the patient's general condition, is not a good 

 sign, but a bad one. In many cases the total number is within 

 the normal limits, but whether this is the case, or whether the 

 leucocytes are slightly increased, a clue to the condition will be 

 given by the fact that the polynuclears show their usual increase, 

 and the glycogen reaction is present and often very marked. 



The haemoglobin, however, gives much more valuable indica- 

 tions ; the severer the case the more rapidly it falls, and vice versa. 

 The same information can be obtained, though not so well, from 



