The Structure and Functions of the haMUolymph Glands and Spleen. 7 



degeneration occurs, as he occasionally finds in them homog-enons 

 pigmented masses. The chief idea in his paper was based on the belief 

 that the so called reticulum consists of branched cells, except inside 

 the lymphoid nodules, and that these cells are capable of assuming 

 phagocytic functions. In some places, near the capsule, Schumacher 

 noticed these cells crowded together to form a dense mass, '' Zwischen- 

 gewehe", completely occluding the sinus at these points, and so crushed 

 together as to have the appearance of solid rods of tissue. In these 

 accumulations he frequently observed the process of karyokinetic divi- 

 sion, the whole mass forming apparently the source of the phagocytes 

 to the rest of the sinuses. Enclosed in the phagocytes he noticed not 

 only erythrocytes, but occasionally, cells which he considered to be 

 leucocytes, and in addition a certain number of rod shaped structures, 

 staining red with eosin. He also gave an account of the cyclic 

 function of the glands, which function he divides into three stages. 

 In his second paper [14\)] was given a more accurate account of blood 

 destruction; he has observed amoeboid movements of phagocytes on 

 the warm stage, but, no actual phagocytosis. 



In 1898, Thome [i5] published a paper in which he advanced 

 the view that phagocytes have their origin in the endothelium cells 

 lining the capillaries of the "Lymphdrüsen" of certain monkeys, and 

 stated that the smaller bloodvessels of the lymphatic tissue are lined 

 by a tall, almost cylindrical endothelium. This statement I have been 

 unable to confirm, but it is in accordance with the view of Böhm 

 and Davidoff [2] in their account of the spleen. 



Weidenreich's first paper [19 -à] was, as he stated, not based on 

 personal observation as far as the bloodlymph glands were concerned, 

 but in his second communication [lOh] he makes some interesting 

 statements of which the following are of the most important. He 

 believes that the well known eosinophile leucocyte of the blood is 

 possessed of its eosinophile granules, on account of its having taken 

 up, while in a bloodlymph gland, particles of disintegrated erythro- 

 cytes; also that such leucocytes may be devoured by a giant cell. 

 He thus supports a theory of direct and indirect phagocytosis. The 

 remainder of liis work is for the most part confirmatory of Schumacher, 



