Ill] 



THE BRACKEN FERN 



43 



its young leaves to carry on the function of self- 

 nourishment. 



It is very beautiful to note in young plants raised 

 by artificial culture how the underground habit of 

 the Bracken is started. The young seedling is in 

 its first stages like any ordinary Fern : but after 

 the formation of half a dozen or so of leaves the 



Fig. 9. A. An archegonium of a Fern, approaching maturity. The 

 protective neck is closed at the apex. m = canal-cell, v.c.c. = 

 ventral canal-cell. o = ovum. B and C, similar archegonia quite 

 mature. The apex of the neck has ruptured, in both cases, and 

 the ovum (o) remains embedded in the prothallus (p), while the 

 open channel of the neck leads down directly to it. (From 

 F. Darwin's Elements.) 



axis bifurcates, and the two equal branches that 

 are formed curve strongly downwards, and bury 

 themselves in the soil. They never emerge again 

 from it in their normal life. Together with the 

 stores of nourishment laid up in their fleshy tissues 

 they are fully protected against extremes of climate, 

 as well as from animal attack. 



