Page:Journal of botany, British and foreign, Volume 9 (1871).djvu/26

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��Ci/sfosipJion pyfhmcles. Any one who lias kept. Wolffiu may have found after a while that many of the fronds become soft, dull, transparent, and of a pale yellow, and sink to the bottom of the water. It was such plants that were found to be affected by the CijHtoslplion. The mycelium of the parasite penetrates the cellular substance of the frond, and the methods of its reproduction are carefully described and figured. There are two modes ; in the asexual mode, which resembles that of FyfMum ento- pliytum, described by Pringsheim in his ' Jahrbiicher,' vol. i. p. 289 and t. 21, zoosporangia are formed in the peripheral cells of the frond, the outer wall of which is ultimately perforated by a slender tube emitted from them ; the extremity of the tube having reached the outer surface of the frond becomes enlarged and forms a vesicle, into which passes the fluid contents of the zoosporangium. This soon divides into several por- tions, each of which becomes a ciliated zoospore. On the rupture of the membrane of the mother-cell these escape into the surrounding water, and after active motion for twenty to fifty minutes settle down on the surface of other fronds of WolJJia, become spherical, acquire a cell-wall, lose their cilia, and germinate by sending out a mycelium, which penetrates the cell- walls of the host-plant. Sexual reproduction is effected by oogonia and antheridia, the contents of which mingle, and that of the oogonium con- tracts into an oval mass (oospore), which soon becomes covered with a thick rugose covering. Its further history has not been traced.

PoTAMOGETON zosTERiFOLius, ScJimn., AT OxFORD. — I have sccn spe- cimens of this rare Pondweed, the P. compressus, L., of Pries, Koch, and the 'Student's Flora,' but not of Linnseus's herbarium, collected in July, 1870, by Professor M. A. Lawson in the Isis, near Oxford. Though the county of Oxford (or Berks) may be considered as hitherto unrecorded for the plant, not being admitted into any of Mr. Watson's summaries, yet, from the references, there is reason to think that by the P. gramineum of Silithorp's ' Flora Oxoniensis ' (p. 66) this species was intended. Few localities are on record in England for this easily-recognized and hand- some species. It is likely to occur in other parts of the Thames water- system. — Henry Trim en.

Flora of Newfoundland. — During an ornithological trip to New- foundland, from August, 1866, to August, 1868, I compiled a list of 372 species of Flowering-plants and Ferns in the island. Of these, the fol- lowing are not included in Sir W. J. Hooker's ' Flora Boreali-Americana ' (1840). The nomenclature is that of Professor A. Wood's 'Class-book of Botany,' New York, 1866.

��Anemone narcissiflora.

Thalictrum alpinum.

Actsea 8j)icata.

Alsine grcenlandica.

Paronychia canadensis.

Scleranthus annuus.

Archangelica peregriiia.

Caucus Carota (intro- duced).

Viburnum Opulus.

V. pauoiflorum.

Centaurea Cyauus (intro- duced).

Calluna vulgaris, Capeliu Bay, 47° N. lat., 53°

— Henry Reeks.

��W. long, (see Journ.

of Bot. II. 55, 154;

111.29,121; IV. 305.) Utricularia minor. Betula nigra. Pinus mitis. Typba angustifolia. Zostera marina. Cypripedium candidum. Spirauthes latifolia. Juncus debilis. J. acuininatus. J. Conradi. Eleoeharis tenuis. Cladium mariscoides.

��Carex formosa. C. comosa. Agrostis scabra. Panicum dichotomum. P. lanuginosum. Bromus ciliatus. Poa trivialis. Glyceria maritima. Briza media (introduced). Lolium perenne (intro- duced). Spartina juncea. S. alterniflora. Osniunda regalis. O. Claytoniana.

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