204 



universal in the high regions. In spots free from snow and furnished 

 with earth, phanerogamous plants, as well as mosses and lichens, are 

 found far above the snow-line. Among the species which are found 

 at the extremest limits in the Central and Southern Alps, at 10,000 to 

 11,000 Paris feet high, are Androsace glacialis and A, Helvetica, 

 Cerastium latifolium, Cherleria sedoides. Chrysanthemum alpinum, 

 Gentiana Bavarica, Ranunculus glacialis, Saxifraga bryoides, S. op- 

 positifolia, Silene acaulis, &c. &c. The extreme limit of mosses is 

 in general little above that of phanerogamous plants. The last 

 lichens are to be found on the highest summits of the Alps, attached 

 to projecting rocks, without any limitation of height. The number of 

 species and varieties, up to this time between 40 and 45 species, which 

 have been found in the Alps between 10,000 and 14,780 Paris feet, is 

 not inconsiderable, but this vegetation is liiuited to very few spots, 

 surrounded by extensive masses of snow. Among the Lecideae, Par- 

 meliae and Urabilicarise, collected by Saussure, Agassiz, and them- 

 selves, on the highest Localities, Dr. Schlagintweit enumerated Lecidea 

 geographica, L. confluens, Parmelia elegans, P. varia, P. polytropa, 

 Umbilicaria proboscidea, ft. ci/lindrica, &c. 



Memoir on the Position of the Carpels ivhen two and when single, 

 including Outlines of a new Method of Arrangement of the Orders 

 of Exogens, and Observations on the Structure of Ovaries consist- 

 ing of a single Carpel. By Benj. Clarke, Esq. 



In this memoir Mr. Clarke details the results of his observations 

 on the position of single and double carpella in reference to axis, 

 with the view of ascertaining the mode in which the reduction of the 

 carpella from a higher number takes place, and the value of the cha- 

 racters thus obtained in the formation of a natural arrangement of 

 plants. He commences with dicarpous ovaries, in which he observes 

 three different positions in relation to axis : 1st, right and left, result- 

 ing generally (as he believes to be shown by an examination of the 

 genus Carex and of certain Malpighiaceai and Euphorbiaceae from the 

 suppression of a third and usually posterior carpellum, but occasion- 

 ally also (as for example in Lonicera, Fortunea, Diosma, and probably 

 Crucifera?) from the abortion of the anterior and posterior carpella of 

 an ovary originally consisting of four divisions ; 2ndly, anterior and 

 posterior, resulting in Houttuynia cordata from the disappearance of 



