THE LIFE OF A FERN. 



II 



If we carefully (every thing in the study of 

 ferns must be done with care) dig up, in August, 

 a plant of Pteris aquilina^ we shall find, that, 

 beyond the base of the fronds perfected the pres- 

 ent season (see a, in PI. 5, Fig. 10), there is 

 a short, woolly-covered, rudimentary frond {b), 

 which, if nicely dissected, will be found to have 

 the beginning of the portion which is to expand 

 next season closely folded over on its summit. 

 Still farther on, along the underground stem, we 

 shall discover at its extreme end (marked c) the 

 rudiment of the frond for the third season, which 

 is not to see the Hght for two years. At d is the 

 continuation of the rhizome : in nature the stem 

 will be more extended than in the figure, as the 

 distances between the fronds will be proportionally 

 greater. If we examine the crown of a tree-fern, 

 or AspidiiLin sphmlosum, or A. marginale, we shall 

 find circle within circle of little heads, the rudi- 

 mentary fronds for succeeding years. As the 

 outermost of these develop year by year, fresh 

 ones are formed at the centre to keep up the 

 supply. If we now imagine the tree-fern laid 

 upon its side just beneath the surface of the 

 ground, and its crown turned up at the end so as 

 to allow the fronds to assume an erect position, 

 we shall have something very much like the As- 

 pidiuiHy or perhaps more like a Strut Jiiopteris. To 

 follow out the comparison still more, it is only 



