Notes on the Sex of the Gametophyte of Onoclea struthiopteris

David M. Mottier
1910 Botanical Gazette  
During the past two or three years the writer has been collecting data from a study upon the gametophyte of Onoclea Struthiopteris with reference especially to the dioecious character of the prothallia, and while this study is in no way completed, it has been deemed advisable to make public some of the facts observed, inasmuch as the data obtained supplement those set forth in a very interesting paper, appearing in a recent number of this journal, by Miss WUIST.' The impression is general that
more » ... on is general that the prothallia of Onoclea Struthiopteris are dioecious,2 and although this is generally true, it is not strictly so, as bisexual prothallia may readily be found under ordinary and perhaps optimum cultural conditions. In I907, in an address before the Indiana Academy of Science,3 I made the following statement: The writer has recently begun the study of a fern, whose prothallia have been reported as strictly dioecious, and if the spores of the same are well nourished, female prothallia will predominate, while with poor nourishment the vast majority of spores will give rise to male gametophytes. An examination of cultures grown under favorable conditions for laboratory use, in which the spores were sown thickly, showed that certain spores produced strictly male plants, others female, and still others bisexual prothallia. A small number of spores were isolated and grown under similar and very favorable conditions, with similar results. The pure males were almost equal in number to those bearing the female organs, while the bisexual plants were few, being about 4 per cent of the whole number. The foregoing results seem to lend encouragement to the view that environmental conditions may have much less to do with the development of male and female prothallia than had hitherto been supposed. The very brief study showed clearly that in the fern in question I WUIST, ELIZABETH DOROTHY, The physiological conditions for the development of monoecious prothallia in Onoclea Struthiopteris. BOT. GAZETTE 49:2i6-2I9. I9I0. 2 CAMPBELL, D. H., Mosses and ferns. Edition 2, p. 3I4. I905. 3 MOTTIER, D. M., History and control of sex. Proc. Ind. Acad. Sci. I907. pp. 44-45. 209] [Botanical Gazette, vol. 50
doi:10.1086/330332 fatcat:ivc26gm4tfenpi7udi3hrt63m4