1907.] Fatty Degeneration of the Blood. 435 



degenerating cells in the blood may recover, like those, e.g., of the kidney in 

 toxic diseases, in which the damage done to the renal epithelium is shown by 

 the temporary presence of albumen and casts in the urine. 



In all the cases we have examined the fatty changes were confined to the 

 finely granular polymorphonuclear leucocytes, that is, to the cells which 

 take the active part in phagocytosis ; the most active cells, as being the more 

 highly differentiated, are those most affected by the toxin. 



We have never seen any such change in the lymphocytes — a class of cell 

 devoid of phagocytic power. 



The inactivity of the lymphocytes is a striking comment upon the fanciful 

 views once held, that the lymphatic tissue, whether of the tonsils, lymphatic 

 glands, or intestinal track, constituted a highly important line of defence 

 against microbial invasion. As a matter of observation it is in the solitary 

 and Peyerian glands of the intestine that tubercular infection takes place ; 

 and once a tubercular process has commenced in a member of a lymphatic 

 chain it spreads from gland to gland until the whole are involved. 



Ancemia. 



In this group of diseases the following of the cases in which fat was found 

 in the leucocytes may be placed : — 



(1) Chlorosis. 



(2) Carcinoma of the pylorus, associated with anaemia of the chlorotic 

 type. 



In chlorosis the fatty changes occurring in the finely granular poly- 

 morphonuclear leucocytes are attributable to the deficient oxygen-carrying 

 power of the blood. No direct observations upon the state of the organs 

 appear to have been made in this disease, although it is commonly assumed 

 that they are affected with fatty degeneration ; the dilatation of the heart 

 observed clinically being especially so explained. Observations upon the 

 blood-forming organs are equally wanting. 



In chlorosis the most marked change in the blood is the excess of water — 

 hydrsemic plethora. The number of red cells in a given volume is 

 diminished ; the absolute number is increased ; and similarly, whilst the 

 percentage of haemoglobin may be reduced to 40 or even to 30, the total 

 haemoglobin content remains normal, and the oxygen-capacity undiminished. 



As the reduction in the oxygen-carrying power affects the tissues supplied 

 by the blood, so it may affect the nutrition of the leucocytes in the blood 

 itself. 



In the particular case of chlorosis in which fat occurred in the leucocytes 

 the blood was taken at 2 o'clock p.m., the patient having had no food since 



