188 ROCHESTER ACADEMY OF SCIENCE. [June 22, 
northern shores swept by the waves of the polar ocean, its western 
boundary by the Atlantic, its southern by the North and the Baltic 
seas, and its eastern by a great gulf, has an atmosphere and a general 
temperature well adapted to the wants of the plant, and it grows 
throughout that region, even extending within the arctic circle. 
‘he condition of humidity is the one of prime importance to this 
species; it can maintain itself in a warm climate if shaded from a bright 
sun and near the water. So, in its southern localities it grows in hilly 
and mountainous regions traversed by streams and in other places 
where its necessary conditions are met. Hooker, in ** British Ferns,” 
says it “is found in the cold and temperate regions of the globe ; 
throughout Europe to its extreme south ; North Africa, Madeira, the 
Canaries, and Azores. In Siberia we possess specimens from the 
Amur, from Manchouria, and from Japan, from Erzeroum ; but in the 
more tropical parts of Asia it seems unknown, even in the great Him- 
alayan range, which exhibits so many European forms. In North 
America, in the United States and Canada, and in the Hudson’s Bay 
territories, it is frequent. East of the Rocky Mountains, and in 
California, whence I have seen it only from Benicia, (A. B. Eaton, 
U.S. Army), the fronds are larger, much acuminated, yet not univer- 
sally so. South of California, on the great continent of America, I am 
not prepared to say it exists. Eaton, in t’‘ Ferns of North America,” 
says: “The North American range exténds from the Atlantic to the 
Pacific, and from the Slave River and Winnipeg Valley to the moun- 
tains of Colorado, Arkansas and North Carolina, and probably tothose 
of Alabamaalso. * * * ‘Throughout Europe and Northern Asia to 
Kamtschatka and Japan ; Azores, Madeira, Barbarv States, and Cape 
Colony. Mexico and the Hawaiian Islands are also mentioned by 
some authors; but the evidence is not satisfactory.” A climate like 
that of Great Britain, with its humid atmosphere, might be supposed, 
as it really is, well adapted to the wants of this plant. Hooker says of 
it: {Common throughout England, Scotland and Ireland, on old 
banks, walls, rocks, mossy trunks of trees, etc.’”’ And George W. 
Johnson, another English author, says: §“ This species is common 
throughout the British Islands on old walls, old roofs of cottages, shady 
banks, and trunks of old trees.”’ It is not found in Florida. Chapman 
mentions, for the Southern States, ||‘ Mossy rocks, etc., in shady 
woods, in the upper districts of Alabama, and northward.” ‘These 
references are sufficient in evidence that this plant disappears in the 
hot and arid regions and delights in coolness and humidity ; and with 
*Hooker, British Ferns, t. 2. 
+Eaton, Ferns of North America, Vol. t, p. 238. 
+Hooker, British Ferns, t. 2. 
§ Johnson, British Ferns, p. 228. 
|| Chapman, Fiora of the Southern United States, 2d Ed., p. 588. 
