ferns. 
55 
the barren clays of North Devon. It is 
difficult to imagine the former existence of 
luxuriant vegetation in many of the heath 
covered spots where their remains now pre¬ 
vail. As we have turned up these chiselled 
fragments of Indian growth in some slate 
quarry amidst our moorland districts, they 
have come to us like unexpected couplets 
of poetry amidst a world of prose. 
The caUimus w^as contemporary with the 
earliest vegetation of which earth affords us 
a record; it became extinct on the floor of 
the new red sandstone, and its smaller ally 
the equisetum succeeded it, and persists to 
the present day. 
The next family is that of the Ferns, 
whose graceful feathery forms, giving ele¬ 
gance to the foreground of the wildest land¬ 
scapes are familiar to all. They are found 
in every region of the globe, but wide dis¬ 
tinctions obtain between species in different 
climates. With us, although varied and 
beautiful in outline, yet they are of subor¬ 
dinate magnitude, compared to their de¬ 
velopment in hotter climates, where they 
become arborescent, and attain a height of 
