THE DUCTLESS GLANDS 1247 



disease, such as recurrent fever, the splenic cells are observed towards the 

 end of the attack to be full of the organism spirillum which is the cause of 

 the disease. In fact these cells are so arranged that they can take up solid 

 particles held in suspension in the blood plasma. We must indeed look 

 upon the spleen as the great blood filter, purifying the blood in its passage by 

 taking up particles of foreign matter and effete red corpuscles. The process 

 of phagocytosis, which was described under the cellular mechanisms of 

 defence (p. 1071), is in the spleen a normal occurrence. 



FIG. 565. Cells from a scraping of the spleen. (KOLLIKER.) 



A, splenic pulp cell containing red blood corpuscles, b (k nucleus); B, leucocyte 

 with polymorphous nucleus; c, pulp cell containing disintegrated red corpuscles; 

 D, lymphocyte ; E, giant cell ; F, nucleated red corpuscles ; G, normal red corpuscle ; 

 ii, nmltinuclear leucocyte ; J, eosinophile cell. 



A function has also been assigned to the spleen in the formation of red 

 blood corpuscles, but the evidence is not sufficient to determine whether 

 such a process occurs normally. 



Chemical analysis of the spleen reveals the presence of a large number of 

 what are called extractives, such as succinic, formic, butyric, and lactic 

 acids, inosit, leucine, xanthine, hypoxanthine, and uric acid. There is also 

 a protein combined with iron, as well as several pigments probably derived 

 from the haemoglobin of the red corpuscles destroyed by the cells of the 

 splenic pulp. The fact that, in cases where the spleen is pathologically 

 enlarged as in leucocythsemia, the uric acid in the urine is largely increased 

 points to a connection between the spleen and the formation of uric acid 

 in the body. The numerous extractives which are found probably owe their 

 origin to the destructive changes effected on the effete constituents of the 

 blood by the agency of the splenic pulp cells. 



