230 



GILBERT MORGAN SMITH 



blue-greens are preserved in the copperrlacto-phenol, the color 

 changes to a bright green in most Nostocaceae and Oscillatoriaceae, 

 and to a brown in the Chroococcaceae. In exceptional cases 

 the blue-green color is retained, but these cases are so rare that the 

 solution should not be used for the preservation of these algae. 



The writer wishes to acknowledge his indebtedness to Professors 

 Charles E. Allen and James B. Overton for their very helpful sug- 

 gestions and criticism during the progress of this work and in the 

 preparation of the manuscript. 



