2oS MICROSCOPIC AND CULTURAL STUDY OF BACTERIA 
the inoculating process by a suitable rotating platform, driven by a 
motor at a speed of 100 to 200 ^e^^olutions per minute. A spiral 
Fig. 24.— Ah agar plate inoculated by the "spiral streak" method. The colonies are 
wholly upon the surface, and the number of isolated colonies suitable for subculture is 
decidedly greater than upon the plate inoculated by the "streak method." 
Fig. 25.— An agar plate inoculated by the "streak method". The colonies are wholly 
upon the surface of the medium, but are relatively few in number where the distribution 
is satisfactory for removing isolated single colonies. 
inoculation is thus made which utilizes a much greater proportion of the 
surface of the medium. Also, and this is very important, the inocu- 
