CULTURING OF MARINE ALGAE IN RELATION 

 TO PROBLEMS IN MORPHOLOGY' 



G. F. PAPENFUSS 

 University of California, Berkeley, California 



Up to the present, the green, brown and red marine algae (the 

 only groups taken into account in this article) have been cultured 

 primarily with the purpose of gaining information concerning 

 their developmental morphology and life history. The methods 

 have been crude as judged by the standards of the physiologist, 

 who has to have pure, bacteria-free cultures. But the achieve- 

 ments none the less have been significant, not only with respect 

 to the initial objectives but in the profitable use that has been 

 made of the knowledge obtained for the interpretation of phylo- 

 genetic relationships within the groups. 



CuLTURiNG Methods and Solutions 



Ordinarily, cultures are started from reproductive cells — zo- 

 ospores, aplanospores, gametes, or zygotes. Fertile plants are 

 placed in dishes of filtered sea water and the liberated reproduc- 

 tive cells are allowed to become attached to slides placed along 

 the sides or at the bottom of the containers. In other instances 

 drops of sea water containing reproductive cells are placed on 

 slides or cover glasses and the cells allowed to become attached. 

 It is always necessary, of course, to determine the nature of the 

 cells to be cultured. Are they asexual spores, gametes, or zygotes } 

 Consequently, it frequently is desirable to start the cultures in 

 hanging drops, which facilitate observation of the behavior of the 

 cells and the early stages in their germination. 



The slides or cover glasses with the attached cells are trans- 



^ This paper was prepared during die tenure of a Guggenheim Fel- 

 lowship. 



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