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Reprinted for private circulation from 

 The Botanical Gazette, Vol. LXIV, No. 5, November 1917 



BRIEFER ARTICLES 



APOGAMY IN PHEGOPTERIS POLYPODIOIDES FEE, 



OSMUNDA CINNAMOMEA L., AND O. 



CLAYTONIANA L. 



Apogamous embryos developed on prothallia of Pkegopteris poly- 

 podioides Fee, Osmunda cinnamomea L., and 0. Claytoniana L. in cultures 

 on Prantl's and Knop's full solutions and certain modifications of the 

 Prantl's solution. About 6 months after the spores had been sown, the 

 first cases of apogamy were observed in cultures of Pkegopteris poly- 

 podioides on Prantl's solution with NH4 NO3 omitted. The spores from 

 which the prothallia developed had been collected during the summer 

 from a plant growing on a lawn in Ithaca, New York. The plant did 

 not appear in a normal, healthy condition, doubtless owing to the 

 unfavorable conditions under which it was growing. After the spores 

 were sown upon the nutrient solutions, the cultures were placed before 

 an east window, where the conditions of light and temperature were 

 approximately the same for all. Once each week the prothallia were 

 transferred to fresh nutrient solutions. 



The prothallia, upon which the apogamous embryos developed, were 

 heart-shaped and developed archegonia but no antheridia. The apoga- 

 mous embryo in most cases originated as a slight swelling of the arch- 

 egonial cushion, either on the dorsal or ventral side, at some point near 

 the notch or at the center of the cushion. This swelling gradually 

 increased until a dome-shaped cellular mass was formed, from which 

 the apogamous embryo developed. The parts of the embryo usually 

 appeared in the following order: the leaf or leaves, root, and stem. 

 However, in one case a root appeared before any other member. No foot 

 was formed. In some cases, beside leaves, proliferations, either filamen- 

 tous or slightly expanded at the apices, developed from the cellular mass. 

 October 7, 1916, two series of cultures on the Prantl's and Knop's full 

 nutrient solutions and modifications of the Prantl's solution were made. 

 Fresh spores from the same plant at Ithaca, New York, as well as spores 

 of the same species secured through the kindness of Dr. A. H. Graves 

 from Brooklin, Maine, were used. As soon as the spores were sown upon 

 the nutrient solutions, one series was placed in the greenhouse in bright 

 light, while the other series was kept in the laboratory before an east 

 window. The prothallia were not transferred to fresh solutions, but 



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