The Role of the Phagocyte in Cerebrospinal Meningitis. 433 



increased within their hosts ; hence the progressive increase in the amount 

 of growth. It is also possible that this growth is due to the blood being 

 allowed to stand for such a length of time at incubator temperature. It was 

 noticed that at the end of 24 hours' time it had undergone considerable 

 haemolysis. This would liberate an appreciable quantity of calcium salts 

 which would in turn destroy the action of the saline. Thus a condition 

 would be brought about which would be favourable to an excessive growth 

 of the few germs that might have been taken up by the leucocytes. The 

 accessory growth factor known to be present in the blood would also come 

 into play, and, the inhibiting toxic action of the normal saline being 

 abolished, rapid growth would take place.* 



The main conclusion of our former experiments is therefore borne out 

 again in Experiment 5. Taking Eow III of this experiment, the large 

 growth in the first area, where the leucocytes have remained whole, although 

 exposed to the toxic action of the saline for six hours, as compared with the 

 complete absence of any growth in the second area, where they have been 

 crushed with glass powder and have come under the direct action of the 

 saline, is very striking and is beyond dispute. 



Experiment 6. 



Emulsions of two strains were submitted to the action of the leucocytes. 

 Strain W was an old laboratory culture, isolated from the spinal canal nine 

 months previously. Strain S 1 had been isolated less than a fortnight. 



f A. — Coccus W + leucocytes + normal serum. 



n ... J B.— „ S1+ „ + „ 

 Opsonic mixtures-; r , w , 



r !(J. — ,, VV + „ + immune serum. 



[D.— „ S1+ „ + „ „ 



Microscopic appearance of the mixtures after 15 minutes' incubation : — 



" A." — Showed no agglutination, but the leucocytes contained many cocci, 

 many shades of cocci, and the staining of nearly all of them within the cells 

 was poor, suggesting partial digestion. 



" K." — Showed no agglutination, and very little ingestion of the germs. 

 Organisms stained well. 



* It has long been remarked that all blood media grow the meningococcus with great 

 readiness ; similar results can be obtained with watery and alcoholic extracts of blood. 

 One of our number (C. S.) hopes to show in a forthcoming paper that in nasal secretion 

 such a body is also present, which is undoubtedly of the nature of an accessory food 

 body in all its properties. It is possible that this body present in blood is similar to 

 that found in the nasal secretion, the nasal secretion, in short, obtaining it from the 

 blood. 



