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UNIVERSITY OF WISCONSIN STUDIES 



more highly magnified than the other figures in the cut. The 

 plate became filled with secondary colonies of this kind con- 

 nected by almost microscopic filaments. At d is another type 

 in which the colony is almost entirely filament with an oc- 

 casional bud-like colony. The filament formation is fre- 

 quently limited to fringe-like outgrowths on the margin, as 



shown by the sections of liquefying colonies at e and /. Some- 

 times on a plate filled with smooth, round, solid colonies, an 

 occasional colony like & or g may develop. The type of colony 

 from an individual culture may be variable and, on a 

 single plate, may be found solid smooth colonies, large colonies 

 liquefying in the center, and almost any one of the colonies 

 shown in Fig. 6. Sub-cultures have been made from the dif- 

 ferent types of colonies of a single culture, but these sub- 



