218 STUDY OF THE PHYSIOLOGY OF BACTERIA 



anaerobes. In the case of these last organisms, a preference 

 for more or less oxygen is indicated by the approach to the 

 aerobic or anaerobic type of growth. 



Fig. 149.— Filiform 

 slope culture. X h 



Fig. 150. — Filiform, 

 slightly spreading,slope 

 culture. X i- 



Fig. 151.— Beaded 

 slope culture. X i- 



Along the line of puncture the commonest types are 

 filiform (Fig. 142), which indicates a uniform growth; beaded 

 (Fig. 143), or small separate colonies; villous (Fig. 144), deli- 

 cate lateral outgrowths which do not branch; arborescent, 

 tree-like growths branching laterally from the line. In agar 

 these branchings are usually short and stubby, or technically, 

 papillate. 



