The Stnicture aucl Functions of the hfemolymph Glands and Spleen. 49 



puscles are the sole representations of the lymphoid masses of other 

 members of the series, which elaborate white corpuscles. Further- 

 more, in such masses large arteries usually exist; thus they are found 

 in the Ijnnphoid masses of lymphatic and hciemal lymphatic glands; in 

 the hnemal giand they occur in strands of adenoid tissue in every 

 way comparable to the spherical Malpighian corpuscles of the spleen, 

 which are almost always found to contain small blood vessels cours- 

 ing through them. 



Endothelium and reticulum are common to all the organs and 

 have an identical arrangement in each. The reticulum and trabeculae 

 become more numerous as one ascends the series to the spleen, in 

 which they are particular!}^ dense. This is but natural, as one of 

 the chief functions of reticulum and trabeculae is their supporting 

 property, for they hold the lymphoid tissue in place in the centre 

 of the sinuses; accordingly they are most plentiful in the organ having 

 the widest sinus. 



Further points of resemblance between the members of the series 

 are found in their functions. It is probable that in almost all blood 

 destruction and elaboration of white cells proceeds. 



The chief differences of importance between the various h?emo- 

 lymph glands, lie in their vascular and lymphatic supply. This has 

 already been referred to in previous paragraphs as depending on the 

 relative quantities of the fluids, blood or lymph, supplied to the organs. 

 Thus whereas the lymphatic ducts to the spleen (pi. II. fig. 20) are 

 probably confined to the walls of the blood vessels and the Malpighian 

 corpuscles, blood enters freely into the sinus (spleen pulp). On the 

 other hand the vascular supply of lymphatic glands is comparatively 

 small (pi. II. fig. 17) and it is not yet ascertained that there is any 

 communication between this blood supply and the lymphatic sinuses, 

 which are in connection with large lymph vessels. Between these 

 extremes intermediate forms are found including the haemal lymphatic 

 gland wliich has an abundant blood and lymph supply. 



From this account it will be seen that a complete series of 

 luemolymph organs exists, which may be classified in the order: 

 spleen, hamial gland, Ivi'mal lymphatic gland, and lymphatic gland 



Internationale Monatsschrift für Anat. u. Phys. XX. "* 



