182 



THE FERNS. FILICES. 



Are among the most graceful and elegant plants ; their 

 leaves (fronds) are in some cases entire, in others most beauti- 

 fully divided, and all of them coiled up before opening in a 

 very curious and singular manner, the effect of which is often 

 increased by the main stem being covered thickly with hairs 

 or scales. The seed cases or thecse are borne in different - 

 shaped clusters, mostly on the under side of the frond, some- 

 times with, and sometimes without a cover over them. These 

 thecse are worthy of the most careful inspection by the naked 

 eye their wonderful form and structure is not seen, but under 

 a miscroscope they will be found to consist of a round or oval 

 bag, with a very elegant, jointed band round it. As the seed 

 ripens the band becomes elastic, and at last flies out, and 

 splitting the theca to pieces at the same time with great 

 force, the seeds are jerked out by the sudden motion to the 

 distance of many inches. 



POLYPODY, (Poly podium.) Seed vessels without a cover. 

 SHIELD FERN, (Aspidium.) Seed vessels round and covered. 

 SPLEENWORT, (Asplenium.) Seed vessels long and covered. 

 BRAKE, (Pteris.) Seed vessels along the edge of the frond. 

 HARD FERN, (Blechnum.) Seed vessels along the middle of 

 each lobe of the frond. 



POLYPODY. POLYPODIUM. 

 COMMON POLYPODY. Potypodium vulgare. 



Plate 14, fig. 13. 



In some parts of the Kingdom this is very abundant, and 

 scarcely anywhere rare. Found at all seasons of the year on 

 walls, trees, &c. Its frond (all of it above the ground is thus 

 called) is like a stalked, large, oblong pinnatifid leaf, that is 

 cut down near to the mid-rib on both sides many times. The 

 seed is in little round yellow spots, in two straight rows upon 

 each division or lobe of the frond. The root is creeping and 

 hairy. 



O. S. Wood Polypody, Tender Three-branched Polypody, and Rigid 

 Three-branched Polypody. 



