132 ASPIDIUM NEVADENSE, SIERRA NEVADA SHIELD-FERN. 



Mountain ferns, as a rule, are rather impatient of the summer 

 air of the Eastern States, or of other places at low elevations. It 

 is not that they object so much to the heat as to the dry air of the 

 long summers. Those who would succeed with it under culture 

 should therefore keep it in the shade near some rivulet or foun- 

 tain if such be convenient, or at least under the shade of a rock, 

 wall, or fence during the summer season ; and in the close, moist 

 air of a fern-case during the winter. Species which grow natu- 

 rally on walls, rocks, or open places, do well in rooms when 

 fully exposed to the atmosphere, unless it be charged with 

 sulphurous gases. 



Explanations of the Plate. — i. A rather young plant from a specimen grown at the Arnold 

 Arboretum. 2. Portion of a pinnule, showing the venation, sori, and the scattered 

 resinous dots. 



