THE LEUCOCYTES IN ORGANIC FUNCTIONS. 719 



not concerned in the formation of fibrin, since they remain out- 

 side of the fibrinous net-work or are only accidentally attached 

 to it." We thus have evidence to the effect that basophiles are 

 different from neutrophiles, both chemically and functionally. 



What is the nature of these granules? Miiller is stated to 

 disbelieve "that they are true particles of fat, since they do not 

 give a reaction with osmic acid," while he is credited with the 

 opinion "that they may be bodies resembling fat, but which 

 fail to show the osmic-acid stain." Indeed, the persistence 

 with which this characteristic appearance is noted by investi- 

 gators is noteworthy. Thus, Kolliker, 53 Ranvier, 54 Bizzorero, 55 

 von Limbeck, 56 and Hayem 57 are referred to by Stokes and 

 Wegefarth as having also observed bodies resembling fat-gran- 

 ules in the blood of normal human beings, those of the last- 

 named investigator and others described by Schiefferdecker and 

 Kossel 58 also as fat-granules being thought by Miiller to be 

 identical to those observed by him. That they are fat-Zifce, as 

 thought by Miiller, but not fat, seems to us quite clear. 



Miiller, we have seen, refers (as do other investigators) to 

 the fact that these granules are "highly refractive." As this 

 sign also attends eosinophilic granules, it would appear to have 

 but little differential value; such is not the case, however, 

 when this property is jointly considered with the osmic-acid 

 reaction, for we have here the two main distinctive signs of 

 myelin. "It is extremely refringent," writes Berdal, referring 

 to the latter; and he also alludes to the familiar fact that 

 "myelin treated with osmic acid" stains black. 



Still, if the granules are composed of myelin, the active 

 constituent of the latter, lecithin, should be present, since we 

 found this body not only in the myelin of nerves, but also in 

 that of the neuron and the interior of the dendrites. That 

 some granules do contain this body is evident, inasmuch as 

 Foster, in his review of the physiological chemistry of white 

 corpuscles, writes: "Next in importance to the proteids as con- 



's 3 Kolliker: "Handbuch der Gewebelehre des Menchen," 1867. 

 84 Ranvier: "Traite" Technique d'Histologie," 1875. 

 55 Bizzorero: "Handbuch der kiln. Med.," 1887. 



66 Von Lunbeck: "Grundriss einer klinischen Pathologie des Blutes," 1896. 



67 Hayem: "Du sang et de ses alterations anatcmiques," 1889. 

 " Schiefferdecker and Kossel: Gewebelehre, Bd. xi, 1891. 



