The Naturalist. 



But I find in looking into my herbarium and to published specimetis 

 and ficrures such a gradation between the common truncatulum, with 

 its turbinate capsules, and your ajfine, with its ovato-cylindrical ones, 

 contracted at the mouth, that I know not where the line is to be 

 drawn. If Gymnostomum affine be reckoned a species, then the G. 

 intermedium of authors must be so too. But I confess I had, unless 

 your further observations should confirm your present opinion (and I 

 will be veiy open to conviction) rather, at present, keep them as 

 varieties — G. truncatulum, 13 = G. intei'medium \ y — G. offine. The 

 leaves, I think, afford no character. The asperity of the upper part 

 of the calyptra is so excessively minute that, without the other 

 characters of the plant were paramount, I would not lay much stress 

 upon it. I had the same plant in view in making variety jS of trun- 

 catulum, and mentioned the characters as varying from ovate to 

 oblong."* 



Passing from this subject, the writer compliments Mr. Wilson upon 

 the beauty and accuracy of his sketches. This habit of sketching 

 minute plants was, he said, the best way to understand them 

 thoroughly. " Your MS. observations upon those little favourites of 

 mine, the Jungermanniae," Sir \Villiam wrote : " are admirable, I shall 

 take the liberty of putting them into my own copy of the ' British 

 Jungermannise ' ; those on the mosses I shall keep for my ' Muscologia.' 

 * * I am glad I directed your attention in the ' Muscologia 

 Britannica' to Bryum \_Mnium\ afine, for I have compared your plant 

 with figures and find it to be the true one. I hope you will find it 

 more advanced as to its capsules ; the leaves are quite satisfactory." 



Mr. Wilson, notwithstanding the great authority of his correspon- 

 dent, maintained his ground with regard to Gtmnostomum affi,ne, and 

 Sir Wm. Hooker at length admitted its specific claims. Writing on 

 the 23rd June, 1828, he said : 



■ " Before setting out on my Highland excursion on Wednesday next — 

 when I shall miss your company — I have many letter debts to pay, 

 and amongst them one to you, for from you I have received a very 

 long and very interesting communication. To this communication I 

 have one, and only one objection, namely, that you should have paid a 

 very heavy postage upon it, which entirely belongs to me, and which 

 I should most cheerfully have paid had it amounted to twice as much 

 and contained only half the information that it does. Pray bear this 

 in mind in your future letters. I have already, I think I may say 



* See "Mus. Brit., Ed. II." 



