6 Th. Lewis, 



form, with the spleen on the one hand and ordinary lymphatic glands 

 on the other, almost a continuous series. 



In January 1900, Drummond [4] contributed an article in which 

 he confirmed the chief points of interest in the work of Vincent and 

 Harrison, though he advanced but few new facts. He differed from 

 the last observers in considering that the glands are not developed 

 from ordinary lymphatic glands, and described somewhat more in detail 

 the varieties of cells found in the "hœmolymph glcmds". In addition 

 he gave an account of the blood supply of the organs, throwing out 

 a strong suggestion that the function of blood destruction may be 

 cyclic. 



The latest papers are three articles published by Warthin [iSa, 

 b, c], in American journals. He divides the glands into two varieties, 

 which he terms " splenolymph" and "marroivlijmjih", attributing the 

 functions of blood destruction and blood formation respectively to these 

 varieties. The marrowlymph glands are said to occur in the retro- 

 peritoneal region only, and are possibly pathological. In his last publi- 

 cation [18c], he discusses the two varieties at more length. Warthin's 

 work upon splenolymph glands is to a large extent confirmatory of 

 previous observers, though with the important distinction that he has 

 worked upon the human subject. In his latest contribution he also 

 states, that he considers the reticulum of the sinuses is lined by flat- 

 tened cells, forming two layers, between which larger cells (phagocytes) 

 occur; so that the blood stream is not in actual contact with the 

 reticulum fibres. 



The German writers have apparently occupied themselves for the 

 most part with the lymphatic glands of certain monkeys, although 

 Leydig [10] seems to have the credit of being the first to describe 

 bloodlymph glands, which he did as far back as 1857. 



In 1889, Hoyer [7] described the process of phagocytosis in 

 lymphatic glands. 



Later Schumacher [14 -d, b] contributed an article, in which he 

 described certain appearances in the "Lymphdrüsen" of Macasus rhesus. 

 Amongst his other observations he noticed the lymphatic "germ centres", 

 and considered that some of these may be also situations in which 



