C0LTITATION. 325 



receive tut little sun in winter, and are densely shaded 

 in summer, all filled with, patches of fine fronds, of a 

 number of different species, varying from the delicate 

 hair-like Triehomanes tricoideum, not more than two 

 inches high, to the rohust T. anceps and T. radieans. 



They are grown in square shallow pans and boxes, 

 well drained in the ordinary way, and having about 

 two inches of peat soil mixed with nearly half its bulk 

 of sand and small broken potsherds ; but soft sand- 

 stone is best. For the creeping sorts the soil should 

 be raised in the form of a mound, and for those that 

 have long-extending sarmentums, if soft stone cannot 

 be had, it is desirable to invert a pan or common deep 

 pot, covering it with a layer of soil, as already ex- 

 plained, to which the plant will cling, and soon form a 

 green hillock ; junks of wood answer the purpose ; 

 but in a moist, close, and warm atmosphere, fungi 

 and insects breed, and in a short time the wood 

 decays, causing unnecessary disturbance of the whole 

 mass of the plant. 



The singular genus Lygodium, and its ally Lygo- 

 dictyon, grow naturally in firm soils, generally amongst 

 trees and bushes, their wiry, flexile, climbing fronds 

 growing over and involving everything within their 

 reach iu the most intricate complexity. In most 

 Ferns, " the whole of the divisions of the fronds are 

 formed in the nascent or bud state, and are unfolded 

 as the fronds elongate ; when the whole of the deve- 

 loped parts are unfolded, the frond ceases further ex- 

 tension. This is, however, not the case in Lygodium, 

 SaljAchlcena, Pellea flexuosa, Gymnngramma flexuosa, 

 Odontosoria aculeata, and a few others, the fronds of 

 which are of indefinite extension, their apices con- 



