Lees : Two New Lincolnshire Cryptogams. 101 



tliis Cetraria must have in it, then, to maintain its ground not merely 

 among its own kind on Yorkshire and Scotch mountains, but on 

 level tracts such as abound in Lincolnshire and Norfolk ! The Rev. 

 W. A. Leighton informs me that it also occurs, in plenty too {i.e. 

 holding its own well), at King's Lynn, south of the Wash — a^fact 

 that can only have become known recently, for the station is not 

 included in the last edition of my informant's Lichen Flora— facile 

 princeps amongst handbooks of its class, but by no means easy to use. 



I do not see how the presence of the Lycopodium and Cetraria in 

 Lincoln is to be explained satisfactorily, save in the way I have out- 

 lined. The facts will not admit of two explanations on a par as to 

 probability, as will the existence of the berried Empetrmn nigrum on 

 Thorne Waste by the wells. Plants may be, nay are, often imported 

 into districts foreign to them by wind, by birds, by rivers in spate, 

 a,nd in soil adhering to the roots of planted shrubs or tree's ; but I do 

 not see how the Cetraria could have come to be where it is by any 

 such means. There has never been a large river running from the 

 Pennine chain of hills, through Lincoln to the coast ; and its soils and 

 surface strata are all of a date subsequent to the Trias : whilst I can- 

 not conceive the CetrariG^, if I could the Lycopodium, having been 

 carried by the wind as a spore. I have been obliged lately to reject 

 that supposition even in the case of a fern, Aspletiium lanceolatum, of 

 Atlantic type, that was lately discovered by the Rev. R. A. Gatty of 

 Bradfield, growing in a valley amid the moors north-west of Sheffield 

 — a district in which there are many ice-brought boulders, known to 

 the dale-folk thereabout as " Travellers " or travelled stones. By a 

 preponderance of probabilities I have been induced to include the 

 fern in the Riding flora as a native, although the station is a long 

 way outside the area hitherto assigned to it in our island, but not 

 upon the ground of its having been blown across-country by the 

 breath of South-west Wind, Esq., in the form of spores. 



Again, with regard to the Cetraria I have asked myself, could the 

 fir-trees beneath which it grows have had anything to do with its 

 presence in a wood in such plenty % The woods, though full of fine 

 trees, are not above a hundred years old ; and more than once have I 

 been told since last May that such and such a one used to be an open 

 heathy warren, similar to one now at Linwood near here, where the 

 " Jleindeer Moss " and an allied species (C. aculeata) grow plentifully, 

 and where the Cetraria does not, so far as I have seen. My own 

 question I have, so far, answered by a kind of mental compromise : 

 that the Cetraria vtiigld have been brought in soil at the roots of 



