CONTRACTION OF THE SPLEEN. I51 



(fox) ; while new adenoid tissue is formed in the lymphatic glands, and in Peyer's patches, 

 the parenchyma of the former coming to resemble splenic tissue ( Tizzoni, Eternod). ] 



(2) According to Gerlach and Funke the spleen is a blood-forming gland. The 

 blood of the splenic vein contains far more colourless corpuscles than the blood of the 

 splenic artery (p. 14). Many of these corpuscles undergo fatty degeneration, and 

 disappear in the blood-stream. That colourless blood-corpuscles 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 leukaemia (Bennett (1852), Virchow). Bizzozero and 

 Salvioli found that, several days after severe haemorrhage, the spleen became enlarged, 

 and its parenchyma contained numerous red nucleated haematoblasts. 



(3) Other observers (Kolliker and Ether) regard the spleen as an organ in which 

 coloured blood-corpuscles are destroyed, and they consider the large protoplasmic 

 cells containing pigment granules as a proof of this (p. 12). According to the 

 observations of Kusnetzow, these structures are merely lymph-corpuscles, which, in 

 virtue of their amoeboid movements, have entangled coloured blood-corpuscles. 

 [Such corpuscles exhibit similar properties when placed upon a warm stage.] 

 Similar cells occur in extravasations of blood. The coloured blood -corpuscles within 

 the lymph-cells gradually become disintegrated, and give rise to the production of 

 granules of haematin and other derivatives of haemoglobin. [The spleen contains 

 so much free iron that a section of this organ, especially from a young animal, 

 when treated with Tizzoni's fluid, i.e., with potassic ferrocyanide and hydrochloric 

 acid, gives a distinct blue colour ( 174, 4).] Hence, the spleen contains more 

 iron than corresponds to the amount of blood present in it. When we consider 

 that the spleen contains a large number of extractives derived from the decomposi- 

 tion of proteids, it is very probable that coloured blood-corpuscles are destroyed 

 in the spleen. Further, the juice of the spleen contains salts similar to those that 

 occur in the red blood-corpuscles. 



The blood from the spleen is said to have undergone other changes, but the following state- 

 ment must be accepted with caution : The blood of the splenic vein contains more water and 

 fibrin, its red blood -corpuscles are smaller, brighter, less flattened, more resistant, and do not. 

 form rouleaux ; its haemoglobin crystallises more easily, and there is a large proportion of O 

 during digestion. 



[The spleen has therefore very direct relations to the blood ; in it coloured blood- 

 corpuscles undergo disintegration, it produces colourless corpuscles, and it is said to 

 transform white corpuscles into red.] 



(4) Contraction. In virtue of the plain muscular fibres in its capsule and 

 trabeculae, the spleen undergoes variations in its volume. Stimulation of the spleen 

 or its nerves, by cold, electricity, quinine, eucalyptus, ergot of rye, and other " splenic 

 reagents" causes it to contract, whereby it becomes paler, and its surface may even 

 appear granular. After a meal, the spleen increases in size, and it is usually largest 

 about five hours after digestion has begun, i.e., at a time when the digestive organs 

 have almost finished their work, and have again become less vascular. After a time 

 it regains its original volume. For this reason the spleen was formerly regarded 

 as an apparatus for regulating the amount of blood in the digestive organs. [The 

 congestion of the spleen after a meal is more probably related to the formation of 

 new colourless corpuscles than to the destruction of red corpuscles. It may be, 

 however, that some of the products of digestion are partially acted upon in the 

 spleen, and undergo further change in the liver.] There is a relation between the 

 size of the spleen and that of the liver, for it is found that when the spleen 

 contracts e.g., by stimulation of its nerves the liver becomes enlarged, as if it 

 were injected with more blood than usual (Drosdow and Botschetschkarow). 



[Oncograph. Botkin, and more recently Roy, have studied various conditions 

 which affect the size of the spleen. Roy enclosed the spleen of a dog in a box 

 with rigid walls, the oncograph (oyicos, volume) and filled with oil after the manner 



