BY U. GREIG-SMITFI. 37 



the diagonal and the second half smeared. Thus a thick and a 

 thin seeding were obtained. A second plate was siuiilarh' treated 

 with suspension ii. The surface moisture was then evaporated 

 by exposing the uncovered Petri dishes in the incubator at 37* 

 for half-an-hour, after which the plates were covered, inverted 

 and allowed to incubate for from 1 to 3 days, the longer time 

 being necessary for the growth of the streptococci. 



The media employed were iNIacConkey's lactose bile salt 

 iieutral-red agar, Endo's fuchsiu agar, lactose agar or nutrient 

 agar, with the addition of either 01 c.c. of normal lactic acid or 

 05c.c. of 10% sodium carbonate per 10 c.c. nutrient agar, 

 nutrient gelatine and glucose agar for anaerobic cultivation. 



Anaerobic cultivation did not assist in isolating oreranisnis 

 other than those which were capable of growing aerohically. 

 The anaerobic glucose-agar plates favoured a growth of 

 streptococci, but these were also favoured by the aerobic-acid 

 and especially the alkaline media. Bac. sporogenes enteritidis 

 was specially sought for, but was never found. Deep tubes of 

 glucose-agar inculcated anaerobicall}' did not reveal microbes 

 other than those obtained aerobicall}' upon plates, and the 

 method was rather troublesome on account of tlie formation of 

 gas bubbles and an exudation of bouillon. 



The colonies that developed upon the plates were examined, 

 and probable races and species were picked out and stroked 

 upon agar and gelatin. The condensed water of the agar 

 cultures was examined for the motility of the organisms, and 

 these tests, together with the morphological appearances and 

 reaction to the Gram stain, enabled the bacteria to be thinned 

 -down to a few possible kinds. These were purified by plating 

 on gelatin, and presumably pure colonies were picked out and 

 stroked on agar. From these cultures, Lemco-gelatin with 

 various sugars, etc., litmus-milk, nitrate bouillon, etc., were 

 infected. The non-motile organisms were frequently tested for 

 motility. 



It is possible, by pursuing certain methods of enrichment, to 

 obtain fioni stools a very varied flora containing perhaps Bac. 

 hifidiis, or one of the bacteria grouped under the name Bac. 



