SEMPLE, Memoirs of the Botanic Garden at Chelsea.' London, Printed by Gilbert & Rivington, 1878. (Not published).

ARTICLES IN Journals.—September, 1878.

Grevillea.-M. C. Cooke, Californian Fungi.' — Id., ‘ExtraEuropean Fungi.'-Id., 'On Chatophoma.'-Id., Ravenel's American Fungi' (continued).-Id. and J. B. Ellis, 'New-Jersey Fungi' (continued). J. E. Vize,. Californian Fungi.'-W. Phillips, Californian Fungi.'-W. Arnell, 'A proposal of phænological observations on Mosses.'

American Naturalist.-E. Palmer, Plants used by the Indians of the United States.'

Bot. Zeitung.-C. Steinbrinck, 'Observations on the dehiscence of some dry pericarps, (t. 13).

Flora.-O. Drude, On the application of an analytical key and the arrangement of Families in the new German Floras.'M. Gandoger, Rosæ novæ Galliæ' (continued). — H. Conwentz, 'On a red Foxglove with Peloria flowers.'

Oesterr. Bot. Zeit.-P. Ascherson, Typha minima or Laxmanni?' -L. v. Vukitonovic, 'On Anthyllis tricolor, Vuk.-F. Hauck, 'Alga of the Adriatic' (continued-t. 3).-R. T. Solla, Midsummer Flora of neighbourhood of Görz' (continued).-F. Antoine, 'Botany of Vienna Exhibition' (continued).

Magyar Novenytani Lapok.-L. Simkovics, 'Additions to Flora of Kolozsvar and Torda' (several new hybrids, described in Latin). Silliman's American Journal.-A. Gray, 'Forest Geography and Archæology.'

Bot. Notiser (15th Sept.).-S. O. Lindberg, 'On Dichodontium.'— O. G. Blomberg, On distribution of Scandinavian Lichens.'-V. B. Wittrock, On Linnæa borealis' (continued).

Botanical News.

DR. PFEFFER, of Basle, has become Professor at Tübingen, and DR. H. VÖCHTING, of Berne, fills his place at Basle.

THE BOTANICAL LOCALITY RECORD CLUB desires to enlarge its operations by the investigation of the geographical distribution of Mosses through the British Isles, on the plan of Topographical Botany.' A catalogue of British Mosses has already been issued by the Club, but the funds in hand do not at present allow of the publication of a Report on Mosses. Mr. C. P. Hobkirk, Huddersfield, and Mr. H. Boswell, Oxford, have consented to act as Recorders, and it is hoped that bryologists who are interested in the subject of distribution will send their names to either of these gentlemen or to Dr. H. F. Parsons, Goole.

Original Articles.

ON A NEW SPECIES OF ISOETES FROM IRELAND. BY D. MOORE, PH. D. (TAB. 199.)

ISOETES MOREI.-Corm bilobed, somewhat crescent-shaped at base, the extremities of crescent præmorse, transverse section of corm panduræform in shape, nearly twice as long as broad, with a slight transverse median line from furrow to furrow widening in the centre, solid, of compact tissue; roots smooth, dichotomously branched; leaves numerous, as many as twenty from one corm occasionally, very long, varying from one to two feet or more, slender and flexible, tapering gradually to a setaceous point, semicircular, with wide diaphanous sheaths involute at margin which nearly meet at base and partly overlap the sporangia, colour bright green, lacunes large, tissue loose; macrosporangia comparatively small, in saccate compartments at the bases of the outer leaves, each containing about twenty spores, veil well developed, arched and covering the sporangia two-thirds of their length; lingula triangularly ovate-cordate, as broad as long, of a brownish colour in centre, with diaphanous margins, the latter composed of layers of single cells and more or less entire according to the equal growth of the delicate cells; ligula short, ovoid, with glossopodium and glands rather indistinct; macrospores roundish or slightly triangular, granular on surface especially on basilar half; microspores smooth, or slightly crested on convex margin.

Hab.-Upper Lake Bray, County Wicklow, Ireland, where it is always submerged.

Compared with its nearest ally, Isoetes lacustris, this remarkable form differs in the following particulars :-First, in the leaves being more numerous on strong plants, from three to four times longer than they are in the normal state of that species, only half the diameter, more setaceous, lacunes longer, and tissue looser. Second, in the much broader sheaths of the leaves, which are more involute at their margins, each half of the diaphanous portion being equal in breadth to that of the more solid part of the leaf itself, and reaching farther up towards the top. Third, in the veil which covers the macrosporangia being one half longer, leaving only onethird of the spores naked. Fourth, in the macrosporangia being in more saccate cavities and fewer in number. Fifth, in the smaller microsporangia, which are nearly overlapped by the sheathing bases of the leaf.

Compared with I. setacea, Bosc., it differs, first, in being always [DECEMBER, 1878.]

N. S.

VOL. 7.

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submerged; second, in the corm being bilobed; third, in the leaves being without stomata; fourth, in having the veil developed.

In general outward appearance our Irish plant bears more resemblance to I. setacea, Bosc., and I. Malinverniana, DeNotaris, than it does to I. lacustris. When laid side by side with strong plants of 1. setacea, collected by Gay near Montpellier, and now in the Kew herbarium, as well as strong plants in the herbarium of the British Museum from several collectors, no difference is observable, and even very little when the plants are examined under the microscope. Out of five plants lately received from Professor Martins of the Montpellier University, which had been grown in rather deep water, one had the corm bilobed, another with a very slight third lobe, and the leaves were destitute of stomata. The only difference I could perceive between them and our Irish plant was in the lingula and glossopode, the former being longer, more transparent, with stronger margins, the glands on the glossopode much clearer and better developed, besides the absence of the veil.

Isoetes lacustris has been long known at Lake Bray, but only the normal type, which grows abundantly in the same lake along with our present plant. Leaves of the latter have been picked up by many collectors, but no definite opinion as to their belonging to a distinct form seems to have been expressed until 1871, when A. G. More, Esq., principal Assistant in the Natural History Museum, Dublin, called attention to it in a paper read before the Royal Irish Academy, which was reprinted, by permission of the Academy, as a 'Supplement to Cybele Hibernica,' in 1872. In his observations on I. lacustris Mr. More states, "A long slender form, some of whose fronds measured twenty-six inches in length, is in autumn washed ashore from deep water at Upper Lough Bray." On seeing the leaves collected by Mr. More, it occurred to me that the plant which produced them must be distinct from the ordinary state of I. lacustris. It was not, however, until November, 1876, that I obtained a supply of plants which were growing in situ. These I brought to the Botanic Garden, and had them planted along with plants of I. lacustris, where both preserved their respective forms; I. Morei producing long slender setaceous leaves, floating on the surface of water, as they frequently do at Lake Bray; I. lacustris short stiff subfalcate leaves, remaining under water.

Although our plant differs in so many particulars from the normal state of I. lacustris, it may be only a remarkable abnormal form of it. It is certainly much more distinct from it than I. echinospora is, which differs in no essential particulars, farther than the echinate macrospores and generally smaller more slender setaceous leaves.

It may be the fact that in Northern Europe we have only one true species, I. lacustris; I. echinospora and the present plant, I. Morei, being the extremes of forms of that species? However, the parts which afford specific characters in this genus being so few, and some of them, as we have seen, not very constant, it may be taken for granted that the limits of true species of Isoetes are not yet fully settled. But, either as a species or variety, I trust this

remarkable plant will bear the name of my colleague, A. G. More, Esq., who first called attention to it, and who has contributed in so many instances to the furtherance of British botany.

DESCRIPTION OF TAB. 199. Isoetes Morei, D. Moore, from specimens collected at Lough Bray, Ireland. 1. A complete plant. 2. Vertical section of the corm. 3. Transverse section of the same. 4. Lower portion of a leaf, showing macrosporangium, veil and lingula. 5. Transverse section of microsporangium. 6. Transverse section of leaf. 7. Macrospores.

[N.B.-In section No. 4 the lingula is shewn too narrow at base, with margins more entire than they usually are.]

THE "PRO-EMBRYO" OF CHARA: AN ESSAY IN
MORPHOLOGY.

By SYDNEY H. VINES, B.A., B.Sc., F.L.S., Fellow and Lecturer of Christ's College, Cambridge.

Ir is to the researches of Pringsheim* that we are indebted for our knowledge of the fact that the fertilised oosphere of Chara does not immediately give rise, as had been stated by previous observers, to the sexual plant, but that a comparatively inconspicuous "pro-embryo" (Vorkeim) is developed from it, which presents no differentiation of stem and leaf, from one of the cells of which the axis of the sexual differentiated plant is formed as a lateral outgrowth. The details of the development of the "pro-embryo " have been recently described by De Bary.t From his description and figures it appears that the first stage in its development consists in the disappearance of the granules of starch and fatty matter from the protoplasm occupying the apex (free end) of the cell, and in the formation of a wall at right angles to its long axis as to divide it into two unequal cells-a small apical cell filled with hyaline protoplasm, and a much larger basal cell, the protoplasm of which is full of granules. The basal cell appears to act merely as a depository for nutrient materials to be used in the growth of the "pro-embryo," which is formed from the small apical cell in the following manner :-It is divided into two equal parts by the formation of a wall perpendicular to the first, lying therefore in the plane of the long axis of the oospore. Each of the two cells thus formed grows out into a multicellular filament, the one being the "pro-embryo," the other the "primary root."

It is not necessary to follow the succession of cell-divisions which lead to the formation of these structures, nor is it essential to reproduce here Pringsheim's account of the development of the axis of the sexual plant from one of the cells of the "pro-embryo." What has been said above will be found sufficient to render intelligible the following discussion, which has for its object the elucidation of the morphological significance of the "pro-embryo." *Jahrb. für wiss. Bot.' Bd. iii. 1864, p. 294.

+ 'Bot. Zeitg.' 1875, p. 377 (trans. in Journ. Bot., 1875, p. 298); also 'Nordstedt, and Wahlstedt, Flora,' 1875.

Oospore fertilised oosphere (central cell, gynosphere, ovum).

=

The interpretation given by Pringsheim* of the facts discovered by him is to this effect :-He considers that the structure which springs from the oospore of Chara, and to which he gives the name of "pro-embryo" (Vorkeim), is the exact morphological equivalent of the protonema which is developed from the spore of a Moss, and he infers from the existence in these plants of leafless structures intervening between the spore and the leafy plant, that the Characea and the Muscinea are closely allied. This close relationship is, he believes, placed beyond doubt by the fact that Mosses alone of all plants possess organs which are analogous to the "proembryonic branches" (Zweigvorkeime) of Chara. The researches of Schimper shew that rhizoid prothallia" occur on the stem and leaves of many Mosses.

In proceeding to inquire into the adequacy of this interpretation, it may be at once admitted that the Characea resemble the Muscinea in many points. Pringsheim does not fail to note in his above-mentioned work the similarity in structure and development existing between the nucule of Chara and the archegonium of a Moss. It is usual at the present time ‡ to place the Characea in the class Carposporea, and to speak of the nucule as a carpogonium. The soundness of such a classification becomes questionable when it is remembered that both in structure and development, as well as in the changes which it undergoes in consequence of fertilisation, the nucule of Chara differs absolutely from a typical carpogonium. The central cell (oosphere) of the nucule is surrounded from the first by a multicellular investment, and consequently that formation of a cystocarp around the oosphere after its fertilisation, which is so characteristic of the Carposporea, does not take place in the Characea. It is probably more correct to speak of the nucule of the Characea as being an archegonium.

In a recent paper upon the alternation of generations among the Thallophytes, § Pringsheim groups the Characea with the Fucacea and the Conjugata, as being plants which do not present that dimorphism of the organs of fructification which is essential to the occurrence of alternation of generations. In making this statement he becomes unconsciously illogical. If, as he insists in his first paper, the "pro-embryo" of Chara be homologous with the protonema of a Moss, and if, as he asserts in his second paper, there be no stage in the life-history of Chara which corresponds to to the asexual generation (sporophore ||) of the Moss, it must be admitted that the product of a fertilised oosphere is morphologically equivalent to the product of a germinating spore; that, for instance, the sporogonium of a Moss is equivalent to its pro

*Loc. cit. p. 318, quoting from Monatsber, d. Berl. Akad.', 1862.

Recherches anat. et morphol. sur les Mousses.' Strasbourg, 1848, pp.

66

|| Thiselton Dyer has suggested the word "oophore" as a general expression for the sexual and sporophore" for the asexual generation of plants. These terms are used in this sense throughout this paper.