ON THE DESTEUCTION OF LEUCOCYTES. By William 

 Brodie Brodie, M.B., Muirhcad Demonstrator of Fliydolocjy 

 in the University of Glasyovj. (Plate XVII.) 



The duration of cell life in the body is usually considered to be 

 a limited one, old cells constantly dying off' and being replaced 

 by new ones. In some cases the processes of regeneration and 

 the ultimate fate of the cells are known and can be observed ; 

 but in other cases, although we can distinctly observe the 

 formative process, it is as yet a matter of uncertainty, or indeed 

 quite unknown, what becomes of the eff'ete cells. To this 

 latter class belong the leucocytes which are produced in large 

 numbers in lymphoid tissues in various parts of the body, and 

 from this free multiplication we may infer that they are also 

 constantly disappearing. So far, however, no account seems to 

 have been given of the mode of their disappearance or removal ; 

 indeed, one comparatively recent text-book on physiology 

 states definitely that we are in absolute ignorance as to their 

 fate (1). 



Quite recently, whilst examining some sections of lymphatic 

 glands from a dog, I observed in the lymph spaces of the 

 medulla many large apparently amoeboid cells, containing what 

 appeared to be ingested leucocytes, in varying conditions of 

 disintegration. These phagocytic cells are rather hyaline in 

 appearance, are possessed of a nucleus well defined in out- 

 line, with well-marked nucleolus, and a comparatively small 

 amount of chromatin, so that it does not usually present 

 the appearance of a darkly stained body. Typically, the 

 nucleus may be said to be round or oval in shape, but variations 

 are common, and are evidently due to conditions prevailing 

 within the cell. Perhaps the most frequent of the variant 

 forms is a crescentic one. The ingested nuclei, on the other 

 hand, stain very darkly, at least in the earlier stages of digestion, 

 though their staining power seems to diminish as this proceeds ; 

 also, they lie in vacuoles in the protoplasm of the enclosing cell. 

 In shape and size they resemble for the most part the nuclei of 



