TEE BUCKLER FERNS. 
and becoming shorter and shorter as they near 
the top of the frond, in which they are finally 
merged. The lower pairs of branches, besides 
being larger than those above them, are also 
broader. The branches are again divided into 
leaflets, and these in their turn are either again 
divided or deeply cleft, and the lobes or smaller 
divisions, whether of branches or leaflets, are 
serrated. One peculiarity must be noted. The 
leaflets on the lower side of the mid- stem of the 
branches are longer than those on the upper 
side ; but this disparity gradually decreases 
towards the top of the frond. It is, however, 
remarkably prominent on the lowest pair of 
branches, and the difference between the upper 
and lower leaflets is most marked in the case of 
the four immediately next the rachis on the 
lowest pair of branches. Even on these branches 
the difference between upper and lower leaflets 
gradually decreases towards the point of each 
branch, near which they are, both above and 
below, almost the same in size. 
On every part of the frond the lobes are curled 
backwards, — sometimes almost doubled back ; and 
345 
