192 BACTEEIODOGY. 



Summarized, then, each org-anism is to be studied by 

 making: 



Plates, 



Colonies, 



Hanging-drop examination, 

 Stained preparation. 

 Stab culture in gelatin, 

 Streak culture on potato, or agar, or both. 

 Drawings. 



The laboratory work, during the first few weeks, is carried on as 

 nearly as possible according to the following schedule: 



1st day. —Cleaning up, and plugging of tubes. 



2nd day. — Preparation of gelatin; sterilization and filling of 

 tubes. 



3rd day. — Dilution and mass potato cultures; sterilization of 

 gelatin. 



4th day. — Sterilization of gelatin; use of microscope; hanging- 

 drop work. 



5th day. — Hanging-drop work, continued: simple staining. 



6th day.— Gelatin plates (prodigiosus and Indicus); simple stain- 

 ing, continued. 



7th day. — Study of colonies, stab cultures, etc. 



8th day.— Gelatin plates (red and violet bacilli); Petri dishes 

 {orange sarcine); Esmarch rolls (yellow sarcine). 



9th day.— Study of colonies, stab cultures, etc. 

 10th day.— Gelatin plates (Kiel and fluorescing bacilli); Esmarch 

 dilution potato (prodigiosus); potato tube culture. 



The plating of two organisms, on alternate days, is continued 

 till the non-pathogenic bacteria have been covered. The class then 

 takes up the work on yeasts and moulds, as given in chapter XII. 

 This is followed by the examination of air, water and soil, according 

 to the directions laid down in chapter XIII. The preparation of 

 bouillon and agar completes the first half of the course. 



The class then enters upon the study of pathogenic bacteria, be- 

 ginning with the work on anthrax animals. The study of the anae- 

 robic bacteria is followed by that of the remaining organisms. These 

 are supplied as pure cultures, or in infected animals. 



