44 
Choice Ferns for Amateurs. 
the plumose forms of dift'ereiit species. A popular 
illustration of this character is undoubtedly the 
beautiful Adiantum teneruin Farleye7ise, or, as it is* 
commonly called, A. Farley ens e (Fig. 30), which is 
exclusively increased by division. 
Two other modes of Fern propagation, each of 
them very little known to the public in general, but 
Fig. 30. Frond of the beautiful iAdiantum tenerum Farleyense, 
a well=Known plumose barren form. 
which may be classed among the most important dis- 
coveries of recent years, must be briefly mentioned. 
One has been called Apogamy, which was first ob- 
served by Professor Farlow in connection w^ith the 
well-known Pteris cretica, but which is now known 
to affect several other Ferns, notably N ephrodiuin 
{Lastrea) Filix-mas cristata. With these the young 
Fern is produced as a bud from certain parts of the 
prothallus, without the formation of sexual organs. 
The sexual process, as the name indicates, is in this 
