The Structure and Functions of the ha?molymph Glands and Spleen. 5 1 



white. Glands falling under the heading of ordinary lymphatic glands 

 may have the same function to a slight degree. This takes place 

 by a process of phagocytosis, identical in all. The process as ap- 

 plied to an erj^throcyte is briefly as follows: A red cell is ingested 

 by a phagocyte, and the cell contents are first liberated: the globular 

 mass of hîemogioblin is transformed into granules of bright yellow pig- 

 ment, by a gradual process, extending from the periphery to the centre 

 of the globule. The final product appears to be a substance allied to 

 bilirubin, and is liberated in the adenoid tissue. 



8. In the rat the lower members of the höemolymph series are, 

 in proportion to their size (if not absolutely), more important as 

 destroyers of erj'^throcytes, than the spleen. 



9. The phagocytes are probably derived from any of the endo- 

 thelial cells attached to the wall of the sinus or meshes of the 

 reticulum. It is not impossible that still others may be transformed 

 varieties of leucocytes. 



10. The hœmolymph glands form structurally an almost unbroken 

 series of organs, the simplest or least differentiated being the ordinary 

 lymphatic ylands, while the most highly differentiated is the spleen. 

 Between these extremes are found structures of every possible graduation, 

 including lunnal lymphatic glands^ hernial glands, and accessory spleens. 

 The spleen pulp is not only homologous with the sinus of the lower 

 members of the series, but structurally is almost identical with it. 



This sinus is marked off from the adenoid tissue represented by 

 the a\Ialpighian corpuscles, by a definite endothelium, in every way 

 comparable to that found in typical liiemal glands. 



4* 



