Black : The imbedded antheridium in DRvoPTERrs 569 



fusion of nuclei, their life history, as far as the number of chromo- 

 somes is concerned, is similar to the life history of the apogamous 

 *' Nephrodhijn molle'' described by Yamanouchi. The figures of 

 Yamanouchi, illustrating the development of this apogamous 

 embryo, are not convincing. There is no evidence that the shaded 

 cells in his figure i (Joe. cit. 299) develop into the embryo shown 

 in figure 2<^ {pL id). If apogamy is present in '' Nephrodiiim 

 mollc^' this plant shows greater potentialities than Dryopteris stipu- 

 Jaris at the present time. A study of just how much dryness will 

 cause the development of imbedded antheridia and how much will 

 bring forth apogamy seems desirable. 



While the main object in carrying on this investigation, namely, 

 to obtain apogamy, has not been accomplished, an antheridium has 

 been found that, so far as the writer knows, has not been obtained 

 before. Acknowledgment is due here to the courtesy of Pro- 

 fessor D. H. Campbell, who confirmed the above opinion as to 

 the newmess of such an imbedded antheridium in the higher ferns. 



I wish to express my deep gratitude to Dr. David M. Mottier 

 for his constant advice and encouragement throughout this study. 



Conclusion 



At the present time I have found no apogamy in either Dryop- 

 teris stipidaris or '^ Nephrodiiun molle^ although, as far as I was 

 able to determine, the cultural conditions described by Yamanouchi 

 were repeated. An imbedded antheridium similar to the anther- 

 idia of lower ferns was found on the majority of the prothallia of 

 Dryopteris stipiilmns and on a number of the prothallia o^ 

 '^ Nephrodium moiled In Dryopteris stipidaris^ in addition to 

 imbedded antheridia, deep-seated structures were found, half of 

 which consisted of sperms and the remainder of large cells. In 

 ^^ Nephr odium inolle'^ a deep-seated ^%%- and ventral canal-cell 



were found. 



Indiana University, 

 Bloomington, Indiana. 



