382 WulIst: BRANCHED PROTHALLIA 
SUMMARY 
1. Branched prothallia occurred in cultures of Adzanium 
bellum, A. Capillus-Veneris, A. cardiochlaena, A. cuneatum, A. tra- 
peziforme, Asplenium bulbtferum, A. Filix-femina, A. platyneuron, 
Camptosorus rhizophyllis, Onoclea sensibilis, Phegopteris polypodt- 
oides, Ptertdium aquilinum, 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 
Atkinson, G. F. (’94). The study of the biology of ferns by the collodion 
method. New York. 
Bary, A. de (’78). Ueber apogame Farne und die Erscheinung der 
Apogamie im Allgemeinen. Bot. Zeit. 36: 449-464, 465-480, 48I- 
487. pl. 14. 
Bauke, H. (’78). Zur Kenntniss der sexuellen Generation bei den 
Gattungen Platycerium, Lygodium und Gymnogramme. Bot. Zeit. 
36: 753-759, 769-780. 
Beck, G. (’78). Entwicklungsgeschichte des Prothalliums von Scolo- 
pendrium vulgare Sym. Bot. Zeit. 36: 780. (Abstract.) 
Black, C. (’14). Branched cells in the prothallium of Onoclea sensibilis 
L. Bull. Torrey Club 41: 617-620. pl. 22, 23. 
