23 



not been known to exist below 1,000 feet. The 

 lower limit of Cheilanthes albo-marginata 

 Clarke, Actiniopteris dichotoma Bedd. and 

 Adiantum caudatum L. is 2,000 feet. Adian- 

 turn 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. 

 Ceratopteris 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 



