382 WuisT: Branched prothallia 



Summary 



1. Branched prothallia occurred in cultures of Adiantum 

 bellum, A. Capillus-Veneris, A. cardiochlaena, A. cuneatum, A. tra- 

 peziforme, Asplenium bulbifernm, A. Filix-femina, A. platyneuron, 

 Camptosorus rhizophyllis, Onoclea sensibilis, Phegopieris polypodi- 

 oides, Pteridium aqiiilinum, Scolopendrium vulgare, Woodsia obtusa, 

 and Woodwardia virginica. 



2. Branched prothallia were not confined to one type of 

 culture medium, but developed on distilled water, on soil and on 

 nutrient solutions. 



3. Branches were not developed at any definite period in the 

 life history of the prothallia, but were formed: (a) by any cell of 

 the filament; {b) by divisions of the last cell of the filament; (c) 

 from the margin and apex of the expanded portion of the pro- 

 thallium. 



4. Branching was both dichotomous and monopodial. 



5. A definite relation seemed to exist between branching and 

 nutrition. 



In conclusion I wish to express my thanks to Professor 

 Alexander W. Evans of Yale University and to Dr. C. H. Kauff- 

 man of the University of Michigan, to both of whom I am indebted 

 for valuable suggestions in the preparation of this paper. 



Yale University 



Literature Cited 



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36: 753-759. 769-780. 

 Beck, G. ('78). Entwicklungsgeschichte des Prothalliums von Scolo- 

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