286 THE PROTEAL TREATMENT OF CANCER 



doubt still exists as to how far the other types of leucocytes which 

 we have described can function as phagocytes. It is probable that 

 the lymphocytes, and certainly the large mononuclear or hyaline 

 corpuscles, are endowed with these properties. The granular cor- 

 puscles, namely, eosinophile and basophile, are thought by some 

 to function as unicellular glands and to react to infection, not by 

 englobing the micro-organisms, but by discharging substances 

 stored up in their granules which have a poisonous effect on the 

 micro-organisms, and so prepare them for subsequent ingestion 

 by the polymorphonuclear leucocytes." 



A very striking illustration of the phagocytic activities of leuco- 

 cytes is given in certain abnormal conditions, notably in so-called 

 phagocytic anaemia. This condition is characterized by active 

 phagocytosis of blood cells by other blood cells of normal or ab- 

 normal type in the circulating blood. Ward says of this : "The 

 resulting blood picture is very striking. In one case the phago- 

 cytosis was so pronounced that it was calculated that if all the 

 cells were as actively phagocytic as one which was observed ac- 

 tually in perfect cells on the warm stage, the whole of the red 

 cells of the body would have been destroyed in less than two 

 hours. In this case the destruction produced a fatal anaemia. 

 Other cases have followed transfusion or have been associated 

 with some known haemolytic process such as cholaemia. Isolated 

 phagocytic cells may be met with in malaria and leukaemia and 

 no doubt in other diseases." 



The active share that the large mononuclear leucocyte takes in 

 this process is noted by Ward and graphically depicted in a draw- 

 ing showing large mononuclear phagocytes, "Many of them con- 

 taining several cells or portions of cells which have been caught." 

 One of these mononuclear phagocytes appears to have engulfed 

 no fewer than seven red corpuscles. Another has engulfed two 

 large cells that have the appearance of polynuclears. The picture 

 gives graphic support to the nomenclature of Metchnikoff, who 

 designated the polynuclears as microphages and the large mon- 

 onuclears as macrophages. 



These activities of phagocytes may be recalled in connection 

 with the observations already cited of similar functioning in the 

 removal of the detritus of cancer cells, as noted by Bash ford and 

 his associates. It may be noted also that Walker, in dealing with 

 the effect of certain serums on carcinoma in mice, observes that 

 if pieces of tumor are placed in the serum of a rat which has been 

 injected with extract of mouse testis, degeneration of the cancer 

 cell takes place, the cells being invaded and replaced by leuco- 

 cytes. It does not appear that this observation has been verified 

 by other workers, 'but it has obvious interest in connection with 

 the not dissimilar observations of the other workers already cited. 

 In particular, note the observation of Bash ford, Murray, and 



