THE FERX BULLETIN 



53 



Adiantum pe datum; Ptcris aquilina; Asplenium 

 filix-foentiria, in marshy places between the dunes; 

 Polystichuni acrosticlioidcs, very sparingly; Ncphro- 

 d in m thelypteris, very luxuriant, like the lady fern, in 

 marshy ground; Nephrodium marginalc, the most 

 common fern; Nephrodium cristatum; Nephrodium 

 spinulosutn, wherever there was a rotting chunk of 

 wood; Onoclca scnsibilis, and Onoclca struthiopteris, 

 both very rank; Osmund a regalis and Osmunda eiu- 

 namomca, these last four in marshy spots ; and Botry- 

 chium virginianum, on the sides of the dunes. 



I have been observing the habits of Onoclca scnsi- 

 bilis for many years, even raising plants from the 

 spores to five years old ; caring for other plants for 

 years, changing conditions, and varying my experi- 

 ments, until I have come to the following conclusions: 



When the soil is constantly and evenly moist and 

 unusually rich, and the plant is constantly shaded, it 

 tends to produce its fertile fronds flattened out like the 

 sterile, with all stages to those only partly rolled up. 

 These unrolled fertile fronds do not differ from the 

 rolled up ones, on the same plant, except in this one 

 particular. 



When a heavy screen was changed so that the plants 

 would be in the full light and sun. the fertile fronds 

 produced the rest of the season were as tightly rolled 

 as usual, and it took two years of shading before these 

 plants produced open or unrolled fertile fronds again. 

 Varying the other conditions — moisture and nutri- 

 ment, had similar results, but less marked. 

 Champaign, III. 



