44 Th. Lewis, 



served masses, having" a homogenous structure, in the Ij^mphoid tissue, 

 in which he considers such degeneration is probable, believing that 

 it takes place in a manner similar to that occuring in connective 

 tissue. 



Warthin has suggested a fourth function, the elaboration of red 

 cells. The appearances described have been noticed in the case of 

 the spleen only. The function may be as he suggests pathological, 

 or peculiar to the glands of the human subject. 



A cyclic function has been attributed to the haemal glands by 

 several observers; the view has been based on the fact that different 

 appearances have been noticed at different times in glands taken from 

 the same positions, giving an indication of different phases of activity. 

 Such changes are particularly noticeable in the glands of the rat, 

 though they also occur to a minor extent in many other animals. 

 The glands, in the rat, possess a very thin transparent capsule, con- 

 sequently the nature of the contents of the sinuses may be judged by 

 external appearances: thus they are sometimes brown, sometimes red. 

 Sections of such glands show, in the first case, the sinuses filled with 

 phagocytes containing pigment; little or no blood is present, and the 

 reticulum is indistinct (probably owing to the liberation of endothelial 

 cells). In the second case, the sinuses are seen to be filled with blood, 

 only a few phagocytes are present and the reticulum is conspicuous. 

 Intermediate stages are found, the glands having to the naked eye 

 a mottled red and brown appearance while in sections the sinuses 

 are observed to contain a number of phagocytes and red blood cor- 

 puscles. 



These appearances would seem to be due to the setting free of 

 a number of phagocytes "en masse", into a blood-filled sinus. These 

 cells rapidly ingest the bulk of the erythrocytes present and convert 

 them into pigment. The pigment is set free in the adenoid tissue 

 and is found in this situation in large quantities, especially in those 

 glands which have their sinuses filled Avith blood. The wandering of 

 the phagocytes to the adenoid tissue would leave the sinuses empty, 

 and this may account for the "collapsed" glands occasionally met with. 

 ^ Presumably the collapsed gland is once more distended with blood. 



