BY R. GREIG-SMITH. 677 



It is clear from these experiments that the lower temperature 

 of growth enables the bacteria to be more strongly or more 

 -easily opsonised. This was also noted in a former paper where 

 it was suggested that the lower temperature permitted the 

 elaboration of a greater amount of opsonisable substance in or 

 upon the bacterial cells. A similar experiment was made at a 

 later date with the following results : — 





Cocci per leucocyte. 





i. 



ii. 



Bacteria grown on agar at 37° 



Bacteria grown on agar at 22° 



5-1 



8-6 



3'8 

 69 



It was noted that the bacteria within the phagocytes in the 

 case of the cells grown at 37° w T ere single while those grown at 

 22° were chiefly in pairs. Upon repeating the enumeration and 

 counting the pairs as units, numbers were obtained which were 

 approximately the same. For example, a fifty count of a 22° test 

 gave 183 groups of pairs and units, and counting each pair as 

 consisting of two units, the count came to 318. If the phagocytic 

 indices of the bacteria grown at 22° are multiplied by 0*58 

 { = ^|4), they approximately equal the indices of the bacteria 

 grown at 37°. 



In testing the cells grown in bouillon, it was found that there 

 was little difference in the 24 hours' cultures. In older growths, 

 however, there was a considerable difference, probably resulting 

 from the increased elaboration of anti-opsonin at the higher 

 temperature. 



Bacteria grown in bouillon at 37° - 11 

 Bacteria grown in bouillon at 22°... 11 



iv.*, a three days' culture; vi.*, a four days' culture. 



The addition of dilute acid and alkali. — A test in which the 

 condensed water of an agar culture was added to the mixture of 

 serum and suspension gave an increased phagocytic index. It 

 could not, however, be confirmed. But it led to testing the 

 action of dilute acid and alkali. The proportion of serum to the 



11. 



in. 



IV.* 



v. 



VI. 



711. 



5 



16 



15 



6 



4 



5 4 



8 



16 



26 



7 



8 



6-3 



