23 
not been known to exist below 1,000 feet. The 
lower limit of Cheilanthes albo-marginata 
Clarke, Actimopteris dichotoma Bedd. and 
Adiantum caudatum L. is 2,000 feet. Adian- 
tum lunulatum Burm. does not occur above 
3,000 feet. 
Though a good number of ferns have been 
found to live in water, there is only one, viz. 
Ceratopterts thalictroides Brong., which can 
properly claim to be called a water fern, in 
the sense that it is particularly adapted to live 
in water by reason of its contained air-spaces 
and other peculiarities which distinguish 
aquatic plants. 
6. CULTIVATION OF FERNS 
In the cultivation of ferns the best rule is to 
imitate the conditions under which the indivi- 
dual species grow in their native haunts. But 
as ferns differ considerably in their require- 
ments and it is not possible in an elementary 
book like this to allude to all of them, we have 
attempted only to give a few general hints on 
the cultivation of ferns grown in Bombay. 
These are mostly tropical and require shade, 
shelter, abundance of moisture, together with a 
