Prof. C. S. Sherrington. On Changes in the Blood 



early phase of development. Bat I have never satisfied myself that 

 tin- individuals of a snbvariety became more numerous or less 

 numerous in proportion to the typical cell. All of these forms 

 appeared to be removed together. 



Nor do I believe that the cell without its granules would have 

 in most oases escaped recognition amd passed muster with the 

 other leucocytes. As stated above, the granules re far from being 

 the only distinctive feature of the cell. 



It is quite certain that, when the cells are being or have been 

 reduced to a minimum in the blood, the remaining individuals are 

 usually of perfectly normal granular appearance, active and unim- 

 paired in their amoeboid action. I have, in the stage just previous to 

 the disappearance of the cell from ordinary films, made tt dozen such 

 films and left them, at various temperatures, protected from evapora- 

 tion, and then examined them at different intervals of time to see if 

 they did lose their granulation. 



Many heeraic leucocytes, under certain circumstances, live a 

 long time after removal : from the body (frog's leucocytes aine weeks 

 in vitro,* dog's leucocytes three weeks, kept cool, tn nYrof). It might 

 therefore have been expected that, if blood containing leucocytes 

 which had freed themselves of their secretion granules were removed 

 and kept alive in vitro for a time, the grannies might be reformed. I 

 placed samples of blood in which I was unable to find any leucocytes 

 containing coarse granules in vitro under appropriate conditions, and 

 examined it at repeated intervals ; but I did not succeed in obtaining 

 any reappearance of the coarsely granular cell. A great number of 

 the leucocytes do, and before very long, become granular with fine 

 and medium sized grannies, and these granules are highly refractive 

 and not basophil (t'.e., not micrococci). I have not satisfied myself 

 that they are fatty. The mode 'of their appearance seems to be as 

 follows : 



A great number of the finely granular leucocytes gradually become, 

 as above mentioned, vacnolatcd. The vacuoles contain fluid, and are for 

 the most part small and spherical, Tint some are larger and oval in 

 shape. In most of the small vacuoles a single, fine, highly refracting 

 particle, the size of a small micrococcus, is to "be found, dancing under 

 Brownian movement. In many of the vacuoles no particle at all is 

 discoverable. In the larger vacuoles are obvious ingesta, but the 

 bright particles in the small vacuoles do not seem to be ingesta 

 t.ecause the plasma in which the cells Ire is generally quite free from 

 particles. The cells seem to exhibit the same vacuolation whether 

 they have remained spherical and inactive as regards amoeboid move- 



' Zahn ; cf. V. Kahlden, ' Ber. u. d. Verhandlungen der Path. Ant.,' Sect. . d. 

 10 Intern. Medic. Congress, Berlin, 1890. 



t Sherrington, ' Intern. Congress -of Pbysiol.,' Liege, 1882. 



