PATHOGENIC BACTERIA. 397 



the cover-glass in the usual manner, and staining with carbol- 

 fuchsin diluted i to 9. Also microscopic examination of 

 hanging drops prepared in peptone solution. These prep- 

 arations are made and examined immediately and after 30 

 minutes in the incubator at 37" C, also dried and stained. 

 The peptone solution is described below. 



Gelatin plates should also be made from the same material. 

 These should be made in 2 series of 3 plates each. J'he 

 first tube of melted gelatin is inoculated with a loopful of the 

 stool, preferably from a mucous flake. The other tubes are 

 inoculated in the customary manner, 3 loops from the first to 

 the second, 3 loops from the second to the third. The plates 

 should be placed, at 22° C. for 18 hours and then examined 

 with the low power of the microscope. Impression preparations 

 and smears should also be examined, and pure culture made 

 from colonies. 



Agar plates should also be made in the manner described 

 for gelatin plates, or the loop of material from the stool may be 

 stirred up in 5 c.c. of bouillon, and three plates made from 

 this suspension, using one loopful for each plate. 



Forthermore, 6 tubes, each with 10 c.c. of the peptone 

 solution described below, are inoculated each with i loopful 

 of the feces, and examined with the microscope after 6 to 12 

 hours in the incubator at 37" C. without shaking up the con- 

 tents of the tube. The tube showing organisms most resem- 

 bling cholera is used for the purpose of making plates in agar 

 and in gelatine as described above for plates directly from 

 the stool. 



In addition to the plates, 3 tubes of peptone are inoculated, 

 each with i loopful. The peptone tubes should be warmed to 

 37° C. before they are inoculated. 



Lastly, a flask containing 50 c.c. of the peptone solution is 

 inoculated with i gram of the stool, and examined of 6 to 12 

 hours as above. 



