STUDIES ON JAMAICAN HYMENOPHYLLACEA 
FORREST SHREVE ) 
(WITH EIGHT FIGURES) 
The Hymenophyllaceae, or filmy ferns, are one of the most 
hygrophilous groups of terrestrial plants, and possess a number of 
features of anatomy and physiology in common with aquatics and 
the bryophytes. Although mainly restricted to tropical and sub- 
tropical regions with heavy rainfall and to habitats of high humidity, 
yet some of the species grow as epiphytes in company with brome- 
liads and succulent orchids, a fact which attracted the writer to 
a study of their local distribution and the gross physiology of their 
relation to water supply and atmospheric humidity. 
The results presented in this paper were secured at the Tropical 
Station of the New York Botanical Garden at Cinchona, Jamaica, 
chiefly during the spring of 1906, while the writer was holding the 
Adam T. Bruce Fellowship in the Johns Hopkins University, and 
partly in the summer of 1909 during several months’ absence from 
the Desert Laboratory. Cinchona is at an altitude of 1525 m. and 
is hard by the virgin rain forest, in which the Hymenophyllaceae 
attain to a wealth in species and individuals which cannot be far 
surpassed in any other place in the world. Of the 459 species 
credited to the family by CurisTeNSEN in the Index Filicum, 49 
occur in Jamaica, and 34 of these have been available for study and 
observation. 
Distribution 
VERTICAL AND REGIONAL DISTRIBUTION IN JAMAICA.—JENMAN’ 
lists for Jamaica 23 species of Hymenophyllum and 26 of Tricho- 
manes. For 31 of the total number of species he states the vertical 
distribution as based on his long experience in collecting in various 
parts of the island. His statements indicate that there are but 
5 species found only below ors m. altitude, and 17 found only 
« Jenman, G. S., Synoptical list of Jamaican ferns. Bull. Bot. Dept. of Jamaica, 
nos. 18 and 20, 1890. 
Botanical Gazette, vol. 51] [184 
