l86 J. CASH: EARLY BOTANICAL WORK OF WM. WILSON. 



I spent the day on which your letter was written very dehghtfuUy on the 

 Breidden Hills, Montgomeryshire, whither I went purposely to collect a lot of 

 Potentilla rtipestj-is and some other rarities for my friends Dr. Hooker and Dr. 

 Greville, who had expressed a wish for them. I brought away between 70 and 

 80 specimens of the Potentilla, which, though the only known British station, 

 grows profusely on particular portions of the hill ; a lot of Lychnis viscaria. 

 Geranium sanguineuin, and Bartramia arciiaia in fruit. These, having in view 

 a private opportunity of sending them to Scotland, have since fully occupied me 

 in drying, etc., but having this morning despatched my parcels I hasten to reply 

 to your letter. In the first place I am happy to find there is some prospect of your 

 being able to accompany me on my projected Snowdonian ramble. From your 

 extensive knowledge of Snowdonia I will leave you to fix the plan for that ramble, 

 promising that my friend Salwey, of Oswestry (a learned lichenist), recommends 

 me to examine some excellent old woods near Bettws-y-coed, where he has found 

 some rare lichens, and to go from thence to Capel Curig. It may also be well to 

 state, as we are not yet personally known to each other, that on these occasions I 

 always regard conveniences and accommodations as of secondary importance, and 

 prefer an inferior inn near a good station to a better at some distance, to save time 

 and labour in walking to and fro. I hope soon to hear you have arranged all these 

 matters. I believe I shall not be limited to time on the journey, and conceive the 

 coaches between Holyhead and Shrewsbury will afford us all the helps we want 

 between our pedestrian rambles. 



You have anticipated my intention, had I called on you in Warrington, of 

 offering you anything my herbarium contains which will be interesting. It always 

 gives me great pleasure to be able to furnish any brother botanist with specimens, 

 and many of the best in my own collection have been communicated by others. 

 I need not therefore say how much I felt gratified and obliged by your very liberal 

 and friendly offer which will afford me opportunities of adding your name to those 

 already in my herbarium. With respect to what I can supply, be they few or 

 many, they shall be freely at your service, and if you will bring with you your list 

 of desiderata I will fill up so many of the number as I can ; or if you can point out 

 any place in Chester where they may be left, I will look a few out and send them 

 there at once by private hand. I have duplicates of the Breidden plants named in 

 the first page, and though you are doubtless rich in mosses, it may be in my power 

 to supply some through the liberality of Dr. Greville, who, when I was in 

 Edinburgh last year, gave me most of the British species I had not previously 

 gathered. The beautiful and rare Daltonia splacJmoides you so kindly enclosed is 

 a great acquisition, and I beg to offer you, in this, a morceau of the no less rare 

 and beautiful Schistostega pennata^ gathered by me this spring in Rowter Cavern, 

 Derbyshire, the station of the shining moss I described in the ' Magazine of 

 Natural History.' I can supply you more liberally when we meet ; also with the 

 Castle Dinas Bran fern, which I believe is Cystea (or Cystopteris) dentata, though I 

 have doubted it. I think all the characters in the English Flora cannot be relied 

 on, particularly the distinction drawn between this species and C. fragilis as to 

 the decurrent or non-decurrent leaflets, and the relative size of the fronds of 

 each, which seems to be governed more by situation than by permanent specific 

 differences. I have also what I believe to be Cystopteris fragilis from the same 

 station, which may have caused the confusion. I have not seen Hooker's British 

 Flora, but have sometimes doubted whether C. fragilis and dentata should be 

 considered more than varieties. 



By the way, I am sorry to learn from my friend Edward Forster, of Hale End 

 (a most accurate and acute discriminator of species), that the British Flora shows 

 marks of very great haste ; indeed, Greville pointed out to me two or three 

 blunders while the work was going through the press. It is a pity so excellent a 

 botanist, and of such high authority, should be so careless ; but he' has sadly too 

 many things on hand to hope any of them can sustain the character of his un- 

 rivalled monograph on the Jungermanniae. 



We have what I believe to be Aspidiuvi angulare copiously in a beautiful 

 wood near my residence, as well as in Wynnstay Park, growing intermingled with 

 A. aadeat7Lm ; and I have perceived many specimens with the leaflets more or less 

 curved, stalked, and decurrent ; and, indeed, a series of the gradations of these 

 characters from one species to the other might be selected so as to justify doubt of 



Naturalist, 



