BY R. GREIG SMITH. 



685 



are the most important points, but besides these the experiment 

 showed that the kind of spreader was immaterial. I have tried 

 other spreaders, including a concave cut slide and a cover glass, 

 notched like a fine saw, but have reverted to the original fin. 

 square cover glass as being the most advantageous, and I count 

 the polynuclears along the margins. I find that flaming the 

 slides, to remove traces of fat, is superior to scratching with fine 

 emery cloth. 



Another test confirmed the previous one so far as the regularity 

 of ingestion and the lower phagocytic count are concerned. It is 

 probable that the polymorphonuclears of the "separate" are 

 smaller and more compact than those of the " cream," and that 

 being of one kind the ingestion of the bacteria is generally more 

 regular. 



B. tuberculosis. 

 M. aureus 



50 and 100 counts. 



" cream 



391, 482=873 

 272, 315=592 

 515, 418 = 933 

 386, 464=850 

 536, 485=1021 



separate 



386, 410 = 796 

 260, 241=501 

 405, 376=781 

 393, 431=824 

 444, 474=918 



In the last experiments the "cream" and "separate" were 

 taken from different portions of the same blood. The differences 

 might be more marked if the division between the two kinds 

 were more clearly made. In the following this was accomplished 

 by taking a suspension measuring 7 c.c, putting it into a narrow 

 tube of such calibre that the suspension measured 175 inches. 

 The tube was rotated slowly in the centrifuge, giving the handle 

 20 turns = 580 revolutions of the spindle. The bottom half-inch 

 of deposit was removed and constituted the "separate." The 

 number of the polymorphs in each concentrated suspension was 

 approximately equal. 



' 



50 and 100 counts. 





" separate " 



supernatant 

 suspension. 



Experiment i 



Experiments 



507, 490= 997 

 504, 511 = 1015 



680,636=1316 

 703, 625=1328 



57 



