53 The heights given on the outlines of the Matterhorn accompanying Chap. III., on the geological section in the Appendix, and quoted throughout the book, are after the barometric (mercurial) measurements of Signor F. Giordano in 1866 and 1868. I have ventured to differ from him only in regard to the height of the second tent-platform, and have assigned to it a somewhat lower elevation than his estimate. 54 During this time making the ascent of Monte Rosa. 55 They were not guides by profession. 56 Those which I collected were as follow:—_Myosotis alpestris_, Gm.; _Veronica alpina_, L.; _Linaria alpina_, M.; _Gentiana Bavarica_, L.; _Thlaspi rotundifolium_, Gaud.; _Silene acaulis_, L. (?); _Potentilla_ sp.; _Saxifraga_ sp.; _Saxifraga muscoides_, Wulf. I am indebted for these names to Mr. William Carruthers of the British Museum. These plants ranged from about 10,500 to a little below 13,000 feet, and are the highest which I have seen anywhere in the Alps. Several times this number of species might be collected, I have no doubt, within these limits. I was not endeavouring to make a _flora_ of the Matterhorn, but to obtain those plants which attained the greatest height. Very few lichens are seen on the higher parts of this mountain; their rarity is due, doubtless, to the constant disintegration of the rocks, and the consequent exposure of fresh surfaces. _Silene acaulis_ was the highest plant found by De Saussure on his travels in the Alps. He mentions (§ 2018) that he found a tuft “near the place where I slept on my return (from the ascent of Mont Blanc), about 1780 toises (11,388 feet) above the level of the sea.” Mr. William Mathews and Mr. Charles Packe, who have botanised respectively for many years in the Alps and Pyrenees, have favoured me with the names of the highest plants that they have obtained upon their excursions. Their lists, although not extensive, are interesting as showing the extreme limits attained by some of the hardiest of Alpine plants. Those mentioned by Mr. Mathews are—_Campanula renisia_ (on the Grivola, 12,047 feet); _Saxifraga bryoides_ and _Androsace glacialis_ (on the summits of Mont Emilius, 11,677, and the Ruitor, 11,480); _Ranunculus glacialis_, _Armeria alpina_, and _Pyrethrum alpinum_ (on Monte Viso, from 10,000 to 10,500 feet); _Thlaspi rotundifolium_ and _Saxifraga biflora_ (Monte Viso, about 9500 feet); and _Campanula rotundifolia_ (?), _Artemisia spicata_ (Wulf.), _Aronicum Doronicum_, and _Petrocallis Pyrenaica_ (Col de Seylières, 9247).