INTRODUCTION. 



of air. Very graceful in their feathery form, 

 and elegant in their waving varieties of foliage, 

 when once shooting up in the spring they con- 

 tinue in verdure to live down whole families of 

 their gaudier rivals ; yielding at length only to 

 the frosts of late autumn, and many persisting 

 even then, especially in protected situations. 



And during this time they are a source 

 of renewed interest in their fresh and fresh 

 growth and development. First, we have a 

 flattish or roundish crosier just peeping 

 above its parent soil; then, ere long, we 

 see the head thicken in the inner fold, and 

 gradually throw out little wings below (them- 

 selves, in the more complicate sorts, being 

 similarly curled up at their ends, and after- 

 wards, duly in their turn, evolving them- 

 selves), which next it leaves behind, slowly 

 unrolling itself upwards from them; then 

 another pair, and then the higher progress 

 again ; and so on, till the complete frond or sepa- 

 rate shoot, with its pinnae, pinnules, &c., stands 

 forth in its full youthful shape, to be expanded 

 more widely day by day up to its perfect form. 



The classification of this tribe is according to 

 their fructification (the seed-vessels, their dis- 



