National Geographic : 1925 May
566 THE NATIONAL GEOGRAPHIC MAGAZINE Print from U. S. National Museum SOME "NATURE PRINTS" OF FILMY FERNS The "filmies" are legion and are extremely diverse in form. Four species are here shown: at top, Trichomanes pctersii, one of the smallest ferns in the world; at right, the Kentucky Filmy (Trichomanes boschianum) ; in the center, Hymenophyllum polyanthus; and at left, Tri chomanes capillaccum, the last two common in tropical America. The prints are natural size and are made by exposing the fronds on sensitized paper in an ordinary printing frame. Blue print paper gives good results (see page 563).