276 VIEWS, &C. PHYSIOGNOMY OF PLANTS. 



remaining, raised on the latter the walls of the crypt, which 

 was re-consecrated in 1061, and spread the branches of the 

 rose-tree over its sides." The stem, still living, is nearly 

 27 feet in height, and only 2 inches thick, and spreads across 

 a width of 32 feet over the outer wall of the eastern crypt. 

 It is undoubtedly of very considerable antiquity, and well 

 worthy of the renown it has so long enjoyed throughout 

 Germany. 



If excessive size, in point of organic development, may in 

 general be regarded as a proof of a long protraction of life, 

 special attention is due, among the thalassophytes of the sub- 

 marine vegetable world, to a species of fucus, Macrocystis pyri- 

 fera, Agardh (Fucus giganteus). This marine plant attains, 

 according to Captain Cook and George Forster, a length of 360 

 feet, and exceeds therefore the height of the loftiest Coniferous 

 trees, not excepting Sequoia gigantea, Endl. (Taxodium sem~ 

 pervirens, Hook, and Arnott) of California.* Captain Fitz-Roy 

 has confirmed this statement.! Macrocystis pyrifera grows 

 from 64° south lat. to 45° north lat., as far as the Bay of San 

 Francisco on the north-west coast of the New Continent; 

 indeed Joseph Hooker believes that this species of Fucus 

 advances as far as Kamtschatka. In the waters of the Ant- 

 arctic seas it is even seen floating between the pack-ice. J 

 The cellular band and thread-like structures of the Macro- 

 cystis (which are attached to the bottom of the sea by an 

 adhesive organ resembling a claw) seem to be limited in their 

 length by accidental disturbing causes alone. 



(13) p. 220 — " Phanerogamic plants already recorded in 



herbariums." 



Three questions must be carefully distinguished from one 

 another : 1 . How many species of plants have been described 

 in printed works? 2. How many of those discovered — that 

 is to say included in herbariums — still remain undescribed? 

 3. How many species probably exist on the surface of the 

 earth? Murray's edition of the Linnaean system contains, 

 including cryptogamic plants, only 10,042 species. Willde- 

 now, in his edition of the Species Plantarum from 1797 to 



* Darwin, Journal of Researches into Nat. Flint., 1845, p. 239. 

 f Voyages of the Adventure and Beagle, vol. ii. p. 363. 

 X Flora Antarctica, p. vii, 1 and 178; and Camille Montagne, Bota- 

 nique cryptogame du Voyage de laBonite, 1846, p. 36. 



