12 ROYAL SOCIETY OF CANADA 



one drop of such a stain is added to one drop of blood, thus making a 

 one-quarter per cent mixture. This film is then covered with a cover- 

 slip and ringed about with vaseline. In this strength the stain does 

 not, for a time at least, interfere with the vitality of the cells. The 

 blood plasma assumes a delicate pink shade, in which greenish corpuscles 

 can be seen floating. Most of the " Dust-bodies " do not stain, but 

 occasionally some are found, usually the larger ones, which assume a 

 vivid red colour, thus indicating the presence of hœmoglobin. As the 

 eosinophile and neutrophile granules in dried blood films stain similarly, 

 it seems probable that some at least of the " Dust-bodies " are identical 

 with leucocytic granulations. In one case, I saw a chain of four or 

 five particles in Brownian movement, most of which remained colourless, 

 but one at the head assumed a bright red colour. Evidently the " Dust- 

 bodies " are not all alike. 



It has been mentioned that some of the larger " Dust-bodies," 

 from their size, shape, and peculiar greenish colour, suggest an origin 

 from the red corpuscles. By observation of fresh blood films on a 

 warm stage for some hours, it is easy to /study the various stages of 

 disintegration and fragmentation of the red cells. The earliest and 

 most constant change in the morphology of these cells is the so-called 

 " crenation," whereby the cell assumes a curious horse-chestnut appear- 

 ance (indicated in Fig. 3a). This peculiarity can often be seen in fresh 

 blood in cases of anasmia and fever, but occurs in all blood after it has 

 stood for some time. In some cases I have noticed that the projections 

 from the surface of the red cells are relatively long and needle-like, of 

 about uniform thiclmess and from three to four times as long as they 

 are broad. If one could imagine these to be broken off, they would, in 

 size, shape, and colour, reproduce exactly the appearance of the larger 

 bacilloid " Dust-bodies." 



After the blood has been kept for some hours upon the warm 

 stage, more marked evidences of degeneration of the erythrocytes appear. 

 In addition to crenation, one may see that the red corpuscles tend to 

 break up into a number of smaller globules. About the periphery of 

 the cell, small rounded masses, of similar structure and appearance lo 

 the main body of the cell, make their appearance, so that the cell looks 

 as if it were budding. They vary in size from a minute projection 

 to larger globular masses one quarter the size of the original cell. They 

 are sometimes sessile, but the smaller ones are often attached to the 

 main body of the cell by a delicate, thread-like pedicle (see Fig. 3). 

 The smaller ones are in constant state of agitation and oscillate from 

 side to side in the blood plasma. From their characteristic greenish 

 colour, they are clearly possessed of all the properties of the original 

 cytoplasm, and are undoubtedly to be regarded as degeneration pro- 



