JOHN H. PHILLIPS 247 



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Fig. 1. Suspension of cells obtained from A. elegantlssima. Stained with 

 periodic acid Schiff's. Magnification 900x. 



on the piece of coveislip. Either kind of preparation is incubated 

 at 15°. The cultures are examined microscopically at a magni- 

 fication of lOOx. Figure 2 shows well-developed clones growing on 

 the side of a tube culture. The piece of coverslip may be removed 

 from such cultures and used for more detailed examination. Grow- 

 ing cultures can be maintained in tubes for prolonged periods of 

 time, provided that fresh nutrient solution is added at weekly 

 intervals. A suspension of cells can be obtained for transfer to 

 new cultures by simply scraping some of the growth from the 

 glass surface with a sterile spatula or through the use of lysozyme 

 1.5 mg./ml. in 0.3 M ethylene diamine tetracetic acid adjusted to 

 pH 8.3 with NaOH. In either case, the final dispersal of the 

 clumps of cells requires agitation. Generally, the suspension is 

 drawn back and forth through a pipette. Cell suspensions may be 

 standardized as indicated above; however, complete dispersal is 

 generally not attained. The isolation of clones developing from 



