366 



Wuist: Br.\nched prothallia 



bearing other prothallia." Lagerburg ('06) figured a slightly 

 branched filamentous male gametophyte of Pteridium aquilinum 

 (L.) Kuhn. Pace ('10) described branched filamentous prothallia of 

 an unknown genus, and Black ('15) observed extensive branching 

 among the filamentous prothallia of Onoclea sensibilis L. which had 

 grown in a submerged condition in cultures of distilled water. 



Fig. I. Branched prothallia of Onoclea sensibilis L., X 125. 



Material 

 The branched prothallia described in this paper occurred in 

 cultures which had been made for the study of the comparative 

 length of the filamentous stage in various genera of the Polypodi- 

 aceae. The genera which showed a tendency to branch were the 

 ioWowing : Adiantum, Asplenium, Cafhptosorus , Onoclea, Phegopteris, 

 Polypodium, Pteridium, Scolopendrium, Woodsia and Woodwardia. 

 The spores of these various genera were obtained from several 

 sources. Those of Adiantum were secured from the greenhouse 

 of the botanical department, Cornell University, and those of 

 Phegopteris came from a lawn in Ithaca, New York. The spores 

 of Camptosorus and Scolopendrium. were collected in eastern New 

 York by Mr. Ten Eyck Burr; while those of Asplenium, Onoclea, 



