THE FERX BULLETIN 



91 



Pease. A. S. Cryptogramma Stelleri in Xen' Hamp- 

 shire. Rhodora. March, 1909. 



Saunders, C. F. Scolopendrium vulgare. Fern 

 Bulletin. Ap.. 1909.— Reprint. 



Shepard. T. Hon 1 to Make Blue Print Paper for 

 Fern Prints. Fern Bulletin. Ap.. 1909. 



Simpson, C. T. Collecting in the Everglades. Fern 

 Bulletin. Ap.. 1909. 



Wixslow, E. J. Xotes on Xephrodium Hybrids. 

 Fern Bulletin, Ap.. 1909. 



Stone. G. E. The Power of Grozvth of Ostrich 

 Ferns. Torrey Bulletin. Ap.. 1909. 



The Filmy Ferxs axd Moisture. — One of the 

 principal offices of the roots, stems and veins of ferns 

 is supposed to be the supplying of water to the fronds, 

 but the studies of Forrest Shreve lead him to conclude 

 that the filmy ferns are not in this class. In a paper 

 before the botanical section of the American Associa- 

 tion for the Advancement of Science at the Baltimore 

 meeting he stated that in the Hymenophyllaceae the 

 leaves are the principal absorbing organs. Since most 

 of the filmy ferns are inhabitants of tropical rain- 

 forests living for the most part on the branches of trees 

 remote from soil water, this is not unnatural. Ac- 

 cording to Shreve most Hymenophyllaceae can stand" 

 total submergence in well aerated water for a month, 

 and will live and thrive without liquid water if kept 

 in air of over 90 per cent, humidity. Even single 

 leaves or parts of leaves will grow under such condi- 

 tions. Very few filmy ferns can endure for any length 

 of time a humidity as low as 70 per cent, though some 

 hairv forms are able to do so. 



