[NicHOLLs] SIGNIFICANCE OF "DUST-BODIES" OF THE BLOOD 13 



ducts. When examined still later, more numerous " Dust-bodies " are 

 to be seen with considerable numbers of smaller or larger, greenish 

 bodies, identical in appearance with the microcytes and schistocytes 

 found in severe forms of anaemia. The larger ones may be half the 

 size of an ordinary red corpuscle, while the smaller ones resemble 

 completely the excrescences just described as occurring on the surface 

 of the degenerating red corpuscles. In the case of frog's blood, I have 

 traced an identical sequence of events; in fact, I have watched the 

 process until the cell have entirely disappeared as such. The most 

 elaborate and bizarre forms may be seen, the red corpuscle being often 

 transformed into an irregular conglomeration of larger and smaller 

 globules attached one to the other. 



I have never observed any spontaneous separation between the 

 excrescences referred to and the main body of the cell, but by gentle 

 pressure on the top-cover they can be broken away and then go floating 

 off and present a fairly active Brownian motion. They are then 

 identical, to all appearance, with the larger " Dust-bodies " of greenish 

 colour previously referred to. It is hard, therefore, to avoid the con- 

 clusion that these latter are in reality degeneration products derived 

 from the disintegration of the red corpuscles. 



With regard to the possible derivation of the " Dust-bodies,'' from 

 the hasmatoblasts, I have but little information. The number of the 

 hœmatoblasts varies considerably in different samples of blood. In 

 some cases they are very abundant and seem to be formed as the blood 

 ages. In other cases they are scanty. I have observed no constant 

 relationship between the number of the " Dust-bodies " and that of 

 the hœmatoblasts, nor have 1 ever found the latter to disintegrate into 

 anything resembling the bodies. 



The observations I have just described prove conclusively, to my 

 mind, that, while a few of the " Dust-bodies " are free leucoc)^ic granu- 

 lations, others are the product of the disintegration of the red 

 corpuscles, while certain of them may possibly be broken off fragments 

 of the white cells. In every case I believe it to be, however, a degenera- 

 tive process, for I have added various li\'ing bacteria, such as the 

 bacillus typhi, b. anthracis, b. tuberculosis, and the staphylococcus 

 pyogenes aureus to fresh blood, and I have never observed any active 

 discharge of the granules from the leucocytes, or anything indicating 

 an attempt on the part of the leucocytes to combat bacteria in this way. 

 To the same end I have examined the inflammatory exudate in a case 

 of empyaema, containing streptococci, which I kept at blood heat in 

 the incubator, without finding any such action on the part of the 

 leucocytes. Further corroboration of this conclusion is found in the 

 fact that when fresh blood is kept the "Dust-bodies" increase to a 



