Page:Journal of botany, British and foreign, Volume 9 (1871).djvu/274

 253 PllOCEE'DINGS OF SOCIETIES.

knowledge of the indigenous plants of the district and simplify their study ; and if of comparatively slight value to an advanced botanist, is just the book to recommend to any one in the neighbourhood commencing the investigation of wild plants. We regret to see a rather large number of misprints in the scientific names. We miss, too, altogether from the book Carex montana, one of the most interesting Tuubridge species, — an inexplicable omission.

H. T.

��;groaetihT9S 0f Soncfics.

��DUBLIN.

Dublin Microscopical Club. — March 2Srd. — Professor Tliisclton Dyer showed a section of the fossil named by Principal Dawson Proto- taxites Logani, and with it a section of Taxus, with a view to draw atten- tion to the structural distinctions which seemed to indicate that the so-called Frototaxites was rather allied to some Algal form, — he would sug- gest some of the Codiece (such as Rh'ipozonlum, Kiitzing, Pliyc. Gen. xlii. 3j^ — than to a Gymnosperm. There is no appearance of "disks," both longitudinal and vertical sections indicating that the mass is composed of a number of tubes running in a nearly parallel direction (occasionally bi- furcating, according to Professor Arclier), and a])parently not septate or tapering, and with an intercellular medium, apparently formed of minor tubes. The principal longitudinal tubes appear on transverse section to have a wall concentrically stratified. Principal Dawson, in describing the Devonian rocks of Canada, speaks of the occurrence in the lower beds of the system of " trunks of drifted trees in the sandstones, at first sight re- sembling those oi Bailoxylun. . . . They present," he says, " a regular tissue of long cylindrical fibres, marked on their sides with irregular spiral lines, and very distinct from those of modern Conifers, though their markings suggest the spiral lines on the cells of the genus, whence I have taken the name Prototaxites for these remarkable trunks. They have niedullaiy rays and regular lines of growth, and attained sometimes a diameter of three feet. Unfortunately, we know nothing of their foliage or fruit, and can but suppose that they constitute a prototype of the Coniferous trees, probably very different from any known in the modern world." (Proc. Koyal Inst, vol. vi. pp. 169, 170.) Mr. Carruthers, however, holds the view which he stated in a paper read to the British Association in 1S70, that "the supposed Taxineous wood from the North American Devonians, to which Professor Dawson gave the name of Prototaxites, is a remarkable Alga of enormous size" ('Nature,' Oct. 6th, 1870). Portions of the supposed wood sent from Professor Dawson to Mr. Carruthers exhibit characters which belong to two very distinct plant-structures. One consists ex- clusively of regular parenchyma ; the other, of which the specimens shown to the Cbib were examples, is that to which the description above quoted, applies, at least as far as their microscopic characters. The appearance of " medullary rays " is probably produced by accidental cracks or fissures, no structure corresponding with them being shown by the microscope. The " lines of growth " would have their parallel in the pseudo-exogenous stems of the existing Alga Lessouia, of which Dr. Hooker remarks (' Flora

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