392 Brown: Regeneration in Phegopteris polypodioides 



leaves of the young sporophytes, as in no case did regeneration 



take place with leaves of the older plants. It was thought of 



interest to see if the primary leaves of the young sporophytes of 



Phegopteris polypodioides Fee could regenerate in the manner 



indicated by Goebel, as apogamy had occurred so frequently in 



cultures of this fern. 



Experimental 



Spores of Phegopteris polypodioides were obtained from Brook- 

 lin, Maine, through the kindness of Dr. A. H. Graves. Cultures 

 were started in the early part of October. The spores were sown 

 on Prantl'sand Knop'sfull nutrient solutions and modifications of 

 these solutions. After the spores were sown the cultures were 

 placed before an east window. In an effort to induce apogamy the 

 prothallia were not transferred to fresh nutrient solutions from 

 time to time, but were allowed to develop upon the same nutrient 

 solutions upon which the spores had been sown. As a result 

 growth and development of the prothallia was slower and fewer 

 sporophytes formed, the majority of which were apogamous.* 

 The primary leaves of both normal and apogamous young sporo- 

 phytes were used in the regeneration experiments. 



March 14, 191 7, primary leaves 5-7 mm. in length were cut 

 from the young sporophytes and placed on sand in watch glasses. 

 In some cases the petiole of the leaf was inserted in the sand to 

 a depth of 1-2 mm., placing the blade of the leaf in an upright 

 position. In other cases the leaf was laid on the sand; while in 

 still others various parts of the blades were covered with the sand. 

 The sand in some of the watch glasses was moistened with Knop's 

 and Prantl's full nutrient solutions, while in the others it was 

 moistened with distilled water. All the cultures were placed in 

 large plates and covered with bell jars. The sand was never al- 

 lowed to dry and water was kept standing in the plates. In this 

 way the air under the bell jar was always moist. 



No experiments were tried to see if the leaves would regenerate 

 while attached to the young sporophytes and no such cases were 

 observed among either the solution or soil cultures, although fre- 

 quently the leaves of this and other species of ferns, especially in 



*Wuist, Elizabeth Dorothy. Apogamy in Phegopteris polypodioides Fee, Osmunda 

 cinnamoinea L., and 0. Claytoniana L. Bot. Gaz. 64: 435. 1917. 



