16 ROYAL SOCIETY OF CANADA 



case of Still's Disease (subacute polyarthritis with enlarged spleen and 

 lymphatic glands), where the microscopic field was literally filled with 

 " Dust-bodies." 



The views enunciated above in regard to the nature and significance 

 of the " Dust-bodies " are established by, to my mind, such incontro- 

 vertible facts, that it is perhaps hardly necessary to pursue the subject 

 farther. Still, inasmuch as such careful workers as Stokes and Wege- 

 farth have indicated a possible bearing of the question upon the 

 important subject of immunity, a few additional remarks may not be 

 uncalled for. 



Stokes and Wegefarth, in their paper previously referred to, ad- 

 vance the theory, that "The bactericidal power of the leucocytes of the 

 blood, and of the serum of man and many animals, is due 'to the 

 presence of specific granules, especially the eosinophilic and neutrophilic. 



"When called upon to resist the action of invading bacteria, the 

 granular leucocytes can give up their granules to the surrounding fluids 

 or tissues." In support of these positions, they point to the facts that 

 the free " Dust-bodies " approximate closely in size to the eosinophilic 

 and neutrophilic granulations in man and also in the case of the lower 

 animals to the granules contained within their leucocytes ; that on stand- 

 ing the number of free " Dust-bodies " in the blood increases ; that in 

 hardened preparations of blood large and small granules stain with 

 eosin. They, farther, refer to the theory of Metchnikoff and its modi- 

 fication by Bucliner, which would give to the leucocytes tne chief role 

 in the struggle of the body to combat infectious disease, and also mention 

 briefly the work of Hahn, Bordet, Schattenfroh, Bail, Dziergowski, 

 Denys, and Hanet, whose combined work may be accepted as proving 

 that the leucocytes contain a substance which has the power of inhibiting 

 the growth of many bacteria. Stokes and Wegefarth give also the 

 details of some of their own experiments with the filtered and unfiltered 

 sera of the dog and rabbit, which they made to determine their power 

 to inhibit the growth of bacteria. They shewed that blood deprived 

 of its leucocytes loses its bactericidal properties. By adding other 

 leucocytes to filtered serum they could restore its inhibitory action, 

 although the eventual growth of bacteria was not prevented, owing 

 probably to the nutritive material dissolved out from the red cells. It 

 should be remarked here that, while it is true that there is a general 

 correspondence in size between the " Dust-bodies " and the leucocytic 

 granulations, this is but a very tifling point on which to establish 

 identity. The microchemical reactions described in my own observa- 

 tions, shew that only a few of the " Dust-bodies " can with any 

 probability be regarded as escaped granulations. Prolonged observation 

 indicates that only an occasional granulation escapes, and, when it does 



