FUNCTIONS OF THE SPLEEN. 207 



spleen = 1059 - 1066. [The watery extract of the spleen contains a proteid combined 

 with iron.] 



The Functions of the spleen are. obscure, but we know some facts on 

 which to form a theory. [The spleen differs from other organs in that 

 no very apparent effect is produced by it, so that we must determine 

 its uses in the economy from a consideration of such facts as the follow- 

 ing (1.) The effects of its removal or extirpation. (2.) The changes 

 which the blood undergoes as it passes through it. (3.) Its chemical 

 composition. (4.) The results of experiments upon it. (5.) The 

 effects of diseases.] 



(1.) Extirpation. The spleen may be removed from an animal 

 without the organism suffering any very obvious change (Galen). The 

 human spleen has been successfully removed by Koberle, Pe"an, 

 Zacaralla (1849), and others. As a result (compensatory ?) the lym- 

 phatic glands enlarge, but not constantly, while the blood-forming 

 activity of the red marrow of bone is increased. Small brownish-red 

 patches were observed in the intestines of frogs after extirpation of the 

 spleen. These new formations are regarded by some observers as com- 

 pensatory organs. Tizzoni asserts that new splenic structures are 

 formed in the omentum (horse, dog) after the destruction of the 

 parenchyma and blood-vessels of the spleen. The spleen is absent 

 extremely seldom (Meinhard, Koch, and Wachsmuth). [Schindeler 

 found that animals after extirpation of the spleen became very 

 ravenous, but there was no other marked symptom.] 



Schiff stated that after extirpation of the spleen, the pancreatic juice failed to 

 digest proteids. The evidence in support of this statement is unsatisfactory, and 

 Mosler affirms that this operation has no effect either on gastric or pancreatic diges- 

 tion. Heidenhain also found a similar negative result. The operation ought to 

 be performed on young animals, as old animals often succumb to it. 



(2.) According to Gerlach and Funke the spleen is a BLOOD-FORMING 

 GLAND. As already mentioned (p. 20) the blood of the splenic vein 

 contains far more colourless corpuscles than the blood of the splenic 

 artery. Many of these corpuscles undergo fatty degeneration, and 

 disappear in the blood-stream (Virchow). That colourless blood-cor- 

 puscles are formed within the spleen seems to be proved by the 

 enormous number of these corpuscles which are found in the blood 

 in cases of hyperplasia of the spleen or leukaemia (Bennett, 1852, 

 Virchow). Bizzozero and Salvioli found that several days after severe 

 hsemorrhage, the spleen became enlarged, and its parenchyma contained 

 numerous red nucleated hsemato -blasts. 



According to Schiff, extirpation of the spleen has no effect, either upon the 

 absolute or relative number of coloured or colourless corpuscles. [According to 

 the more accurate observations of Picard and Malassez, there is a temporary 



