344 



TEMPERATURE COEFFICIENT OF PHAGOCYTOSIS 



TABLE III. 



Temperature Coefficients of Phagocytosis by Film Method. 



In each experiment a mixture of quartz particles 4.6 ix in diameter and carbon 

 particles 4.7 n was used. 0.3 cc. of this mixture in distilled water was added to 1 

 cc. of leucocyte suspension plus 0.4 cc. serum plus 0.2 cc. NaCl 2.25 per cent plus 

 0.2 cc. -^ phosphate mixture of pH 7.5. Rates of phagocytosis, K, were taken equal 

 to the reciprocal of the times, T, necessary for the ingestion of 25 per cent, 50 

 per cent, or 75 per cent of the particles. T was determined graphically, ^lo 

 was calculated by equation (2). The dispersion of the average was calculated 

 where the data were adequate. 



SUMMARY. 



1. The experiments of Madsen and Watabiki on the effect of tem- 

 perature on the phagocytosis of bacteria are discussed and a new 

 analysis of their curves is given, showing that the rate of phagocytosis 

 is very nearly a logarithmic function of the temperature from 0° to 

 35°C.; i.e., Qio is constant over that range and is equal to 2.0, 



2. New experiments are reported on the effect of temperature on the 

 phagocytosis of quartz and carbon particles of uniform sizes, showing 

 a marked increase in the temperature coefficient below 30°C. 



