Mr. J. Hogg's Catalogue of Sicilian Plants. 335 



the lower region of Teneriffe, 54 are natives of Sicily" [sed qucere, 

 is not Etna only here meant?] "also. This proportionally large 

 resemblance is owing to the circumstance that many of the plants 

 now found growing wild on the Canary Islands have been introduced 

 from Europe by cultivation." Yet I should refer this resemblance 

 to the like kinds of soils and strata, rather than to any introduction 

 by cultivation, as its true cause ; because, Etna and Teneriffe being 

 both volcanic mountains, it is therefore most natural that many spe- 

 cies of plants should be common to both those mountains, and should 

 be equally indigenous in both those localities, which almost entirely 

 consist of lava and volcanic beds. For a full and a comparative ac- 

 count of the plants of the Canary Isles, I will refer the reader to the 

 * Phytographia Canadensis,' by MM. Barker Webb and Sabin Ber- 

 thelot. 



Fifthly. From Dr. Philippi's memoir it is observed, at page 52 

 ' Comp.,' " not a single Sempervivum grows in Sicily." On the con- 

 trary, the Sempervivum tenuifolium of Smith (in Sibthorp's Fl. Gr. 

 Prod.) is, according to Dr. Gussone, not uncommon near Palermo, 

 Catania, and elsewhere in the island. 



Sixthly. " At Palermo " (continues that extract at p. 49) " the 

 mean temperature is Q3\° of Fahr.*, or 14° of Reaumur. The great- 

 est degree of heat during twenty years was 101 J° Fahr. (31° Reau- 

 mur), and the extreme cold during the same period, 33^° Fahr. 

 nearly, or +0*9° of Reaumur." But it appears more correctly, from 

 the statements of Prof. Scina in his ' Topografia di Palermo,' that 

 the mean annual temperature (in Palermo) was 14'4° Reaumur = 

 64° Fahr. nearly. The greatest degree of heat during twenty years 

 did not exceed 33*3° Reaumur = 106j° Fahr. nearly ; and the ex- 

 treme cold for the same period, + 0*2° Reaumur = 32j° Fahr. 

 nearly. 



The comparative and geographical botanist will find many of the 

 Sicilian plants indigenous in Asia Minor and in the Morea, in the 

 Pyrenees and in Spain, as he will perceive on reference to the late 

 Prof. Don's List of Plants given in Mr. Fellows's * Account of a 

 Second Expedition in Asia Minorf;' to ' Botanique de l'Exped. Scien. 

 de Moree,' par MM. Bory et Chaubard, tome iii. ; to Mr. G. Ben- 

 tham's ' Catalogue des Plantes Indigenes des Pyrenees ;' to Mr. P. 

 B. Webb's 'Iter Hispaniense,' Paris, 1838, and 'Otia Hispanica,' 

 now in the course of publication: also M. Agardh's 'Algae of the 

 Mediterranean,' published this year, will render considerable assist- 

 ance to the algologist in the south of Europe. 



par L. von Buch, traduite par C. Boulanger,' p. 116, Paris, 1836; and like- 

 wise Von Buch's original Essay, with lists of the Plants, in ' Abhandlungen 

 der Konigl. Akadem. in Berlin,' 1817. — J. H. 



* The corresponding degrees on Fahrenheit's scale are not exactly com- 

 puted in the Comp. Bot. Mag. i. p. 49. 



f And also inserted in vol. vii. of this Journal, p. 454. — Ed. 



London, June 16, 1842. 



