434 Messrs. S. G. Shattock and L. S. Dudgeon. [Mar. 18, 



rendered fatty by the toxic action of pyogenic micro-organisms. Indeed, 

 a study of cover-glass films made from the pus of an acute abscess and 

 treated precisely as those of blood reveals the presence of scarlet points and 

 droplets within a large number of the finely granular polymorphonuclear 

 leucocytes, which are exactly matched by those in the leucocytes of certain of 

 the blood films described. In some of the pus cells (as in the blood) the 

 red points are quite minute (as they were in the case of influenzal pleurisy) ; 

 in others larger (as in one of the cases of acute pneumonia) ; or still more 

 so, as they were in the case of pyloric carcinoma associated with chlorotic 

 anaemia. 



It is noteworthy, too, that in the pus cells so affected the nuclei may 

 exhibit no fragmentation. ISfor have we ever seen nuclear fragmentation in 

 the fatty leucocytes in blood films. 



This prognostic conjecture, nevertheless, is not borne out by observation. 



Thus in the three cases of acute pneumonia in which a certain number of 

 the polymorphonuclear leucocytes contained fat, recovery ensued. In one 

 case the blood was examined on the sixth day, two hours after the crisis ; in 

 another on the fifth or sixth day, before the crisis; and in another five 

 hours after the crisis. 



The actual number of leucocytes showing the fatty change in these three 

 cases, however, was not excessive, and although the phagocytic power of such 

 cells would, doubtless, be diminished or destroyed, the great excess of 

 leucocytes present would compensate for such a loss. Within two or three 

 days after the crisis the leucocytosis has disappeared ; the leucocyte count 

 is practically normal. 



This rapid disappearance of the leucocytic excess from the blood is largely 

 due to the vast immigration of leucocytes into the infected organs, the lung 

 more especially ; the surplus yet remaining would disappear, as having no 

 further purpose to serve. For all observation goes to show that the 

 rapid amelioration following the crisis is due to the activity of the finely 

 granular leucocytes. 



' MacDonald* has shown that the opsonic index attains its maximum at the 

 crisis. And Eosenowf concludes from his work that pneumonia serum has 

 no pneumococcidal effect ; that the opsonin during and shortly after crisis (in 

 cases that recover) seems to rise above the normal, and that the pneumo- 

 coccidal action of pneumonic blood is the result of the combined action 

 of serum and leucocytes — phagocytosis and intraphagocytic digestion. It 

 must not be forgotten, moreover, as a general consideration, that the 



* ' Path. Soc. Trans.,' London, vol. 57, p. 45, 1906. 



t 'Journal of Infectious Diseases,' vol. 3, June 30, 1906, Chicago. 



