370 



MANUAL OF PHYSIOLOGY. 



FIG. 102. 



Eeticulura of the Spleen Pulp injected 

 with colorless gelatine. (Cadiat.) (a) 

 Meshes made of endothelium. (6) Lac- 

 unar spaces, through which the blood 

 flows, (c) Nuclei of endothelium. 



able peculiarities. Although so fall of blood, which is generally 

 alkaline, the spleen is acid in reaction, and contains a great quan- 

 tity of the oxidation products 

 (so-called extractives) commonly 

 found as the result of active 

 tissue change. The chief of these 

 are uric acid, leucin, xanthin, 

 hypoxanthin,inosit, lactic, formic, 

 succinic, acetic and butyric acids. 

 It also contains numerous pig- 

 ments, rich in carbon, but little 

 known, which are probably the 

 outcome of destroyed haemoglobin. 

 A peculiarly suggestive constitu- 

 ent is an albuminous body con- 

 taining iron. The ash is found to 

 contain a considerable quantity 



of oxide of iron, to be rich in phosphates and soda, with but 

 small quantities of chlorides and potassium. 



If the blood flowing in the artery to the spleen be compared 

 with that in the vein, the difference gives us the changes the 

 blood has undergone in the organ, and hence is of great import- 

 ance. In the blood of the vein is found an enormous increase in 

 the number of the white corpuscles (1 white to 70 red in the vein, 

 as against 1 to 2000 in the splenic artery). The red corpuscles 

 from the vein are smaller, brighter, less flattened than those of 

 ordinary blood ; they do not form rouleaux, and are more capable 

 of resisting the injurious influence of water. The blood of the 

 splenic vein is also said to have a great proportion of water, and 

 to contain an unusual proportion of uric acid and other products 

 of tissue waste. 



The amounf of blood in the spleen varies greatly at different 

 times. Shortly after meals the organ becomes turgid and remains 

 enlarged during the later periods of digestion. The size of the 

 spleen, which may be taken as a measure of its blood contents, is 

 also altered by many abnormal conditions of the blood. Thus, 

 in all kinds of fever, particularly ague and typhoid, and in syph- 



