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accordingly may readily be conveyed to a distance by the wind and 

 by other means ; and lighting on a situation suitable to their growth, 

 in due course vegetate and spring up. It should almost seem, in- 

 deed, that the earth and the atmosphere are charged (so to speak) 

 with the minute seeds of ferns, mosses and fungi, which are only 

 waiting for favourable circumstances to call them into active life. In 

 this manner I suppose it is that Asplenium Ruta-muraria and Tricho- 

 manes have occasionally appeared, self-invited, in the chinks of my 

 garden-wall and down among the brick-work of the cellar-windows. 

 Moreover, the seeds of ferns, contrary to what I should have expect- 

 ed, are known to retain their vegetative power for a great length of 

 time. I have often raised ferns from seed scraped from old specimens 

 preserved in an herbarium. Ferns therefore, above most other plants, 

 we might expect to meet with every now and then in new localities 

 where they had never occurred before. I will now mention an in- 

 stance of what I consider the spontaneous appearance of a rare, or at 

 least a local species of fern, which occurred to me in the adjoining 

 parish of Berkswell. About two years ago I was greatly surprised as 

 well as gratified at finding Polypodium Diyopteris in the crevices of 

 a rough stone wall by the road-side, half a mile from that village. 

 This wall, which was constructed of rough sandstone, without any 

 mortar, had been built in the year 1829 (?'. e., about seventeen years 

 before I observed the fern), for the purpose of making a facing to se- 

 cure the perpendicular side of the bank, on the occasion of the road 

 having been widened. As many of the more common species, such 

 as Lastreea Filix-mas and dilatata, Athyrium Filix-foemina, Polypo- 

 dium vulgare and Asplenium Adiantum-nigrum, &c, grew originally 

 on the bank before the road was widened, of course they soon esta- 

 blished themselves on the newly-constructed wall, to which they 

 proved a great ornament. In this situation I have often admired, and 

 often gathered A. Adiantum-nigrum, which flourished there profusely, 

 but never, till about two years ago (as already said) did I observe P. 

 Dryopteris on the wall, and then but sparingly, and only in one spot. 

 The following yeai', a friend to whom I had pointed out the fern, 

 found a specimen on another part of the same wall, at the distance, 

 perhaps, of fifteen or twenty yards. I must remark that I have 

 not the slightest suspicion of any botanical fraud (as it is called) 

 having been practised in this instance by any one who might 

 have planted P. .Dryopteris on this wall in order to surprise and 

 deceive other botanists ; this, I think, in the present case ex- 

 tremely improbable. However, should any reader of the ' Phytolo- 



