Go BRITISH FERNS. | 
the stones until all the interstices are filled: on 
watering the surface this light mould will probably 
disappear; it should be repeatedly filled up and 
watered until all the fragments of stone only crop out 
tivating these ferns, recommending the addition of 
loam, as more retentive of moisture. 
The Rev. William Little informs me that Woodsia 
Tlvensis grows freely with him in a cool green-house, 
and also under a frame, but that it thrives still more 
lost it several times. Mr. Little adds that the Moffat 
Hills are of the lower Silurian formation. 
18. BRITTLE FERN. Fraauus. : 
Cystopteris fragilis. B. F’. 87, 92. 
The caudex is elongated horizontally, but very 
slowly, the ousteneiey always having a vertical position, 
and terminating in a crown of unexpanded fronds. 
‘The fronds begin to unfold early in the spring, and 
appear very evanescent, generally arriving at maturity 
in a few weeks; a constant succession of fronds is 
produced throughout the summer and autumn, but all 
the first frosts of winter. The frond is 
