XIV 



THE LYMPH 



549 



splanchnic and semilunar ganglion, from which arises the splenic 

 plexus. 



According to the histological researches of Retzius, v. Kolliker, 

 and Fusari, the nerves of the spleen are usually non-niedullated 

 and for the most part supply the vascular muscles. 



From the above it is evident that the blood which penetrates 

 the spleen by the splenic artery comes into immediate relation with 

 the elements of the splenic pulp contained in the labyrinthine 

 spaces, and that the blood which issues from the spleen by the 

 splenic vein must have traversed the lacunar system. 



On examining the mobile elements of the splenic pulp undei 

 the microscope, they are seen to consist for the most part of 

 erythrocytes and leucocytes, i.e. of the corpuscles of normal blood, 

 which, owing to the marked circulatory delay within the lacunar 

 system, become concentrated with very little plasma. 



Besides the ordinary red and white blood-corpuscles, however, 



FKJ. '2<>3. Splenic cells of various forms and sizes, containing in tlieir cytoplasm pigment 

 granules, and erythrocytes in process of dissolution, or fragments of already dissolved 

 erythrocytes : magnification of 1'JCO diameters. (From a dry preparation of F. Miiller.) 



the splenic pulp contains other elements, similar to those of bone 

 marrow. Megacaryocytes are rare, at least in man ; on the other 

 hand, there is an abundance of smaller amoeboid cells (although 

 still twice the size of common leucocytes), many of which exhibit 

 erythrocytes in process of breaking up (globuliferous splenic cells) 

 inside them. There are many intermediate forms between the 

 ordinary leucocytes and the globuliferous cells, all containing in 

 their protoplasm extraneous corpuscles of varying form and 

 magnitude, which represent pigment granules or the detritus of 

 erythrocytes ingested by phagocytes (Kolliker and Ecker; Fig. 

 263). The plasma, again, in which these amoeboid cells are 

 suspended, contains, in addition to the normal erythrocytes^'a 

 certain number of red corpuscles which are at different stages* oT 

 disruption, and pigment granules Derived from the decomposition 

 of haemoglobin. 



In the spleen of very young animals, there are constantly 

 present along with the erythrocytes a greater or less number of 

 erythroblasts or nucleated red corpuscles in various stages of 



