The fact that the cells themselves increase in size during the formation of mucilage, necessitates the hypothesis that intussusception takes an active part in the formation of all those layers which are formed before the completion of the growth of the cells. If growth took place by apposition only, the layers would be formed only after the cells had obtained their full size.

The walls of the mucilage-tubes do not assume a condition capable of swelling during their development, but retain their structure to the end. The death of the thallus causes the tubes to open in succession and discharge their contents. The disorganization of the mucilage-cells in the end of the thallus takes place in the

same way.

Nothing can be said with certainty with regard to the physiological function of the mucilage-organs of the Marchantiaceae, but it is probably connected with their great power of swelling, owing to the capacity of their contents for absorbing water.

Characeæ.

Characes of the Argentine Republic.*-C. Spegazzini describes six species of Nitella, with four forms, one of Lamprothamnus, and three of Chara, with two forms. The species of Lamprothamnus is new, and is thus described :-L. Montevidensis Speg. Maximus, crassus, capitato ramosus, ecorticatus, monoicus. Antheridia globoso-polygona, rufo-fusca v. rufo-rubra (0·20-0·22 mm. diam.); sporangia ad basin antheridiorum enata, infera, globosa (0·30-0·35 mm. diam.), rubescentia, subinconspicue 5-7 gyrata, apice coronula mammiforme, obtusa breviusculaque ornata. Near Montevideo.

American Species of Tolypella.t-The two families into which the Characes may be divided are distinguished by the structure of the corona of the sporangium (archegonium), which consists in the Chares of five, in the Nitelles of ten cells; in some species of the latter family it is evanescent. The Nitellen again may be divided into two genera, distinguished chiefly by the position of the antheridium, which in Nitella is apical, on the primary ray of the leaf, the archegonia being lateral on the node below the antheridium; and the leaves having but one leaf-bearing node. In Tolypella the antheridia are one or several, lateral on the nodes of the leaf and leaflet; the leaves have from one to three nodes bearing leaflets.

T. F. Allen gives a full account of the American species of Tolypella, and proposes the following general classification of the twelve known species of the genus, of which four are now described for the first time :

I. OBTUSIFOLIA.-Corona evanescent; sterile leaves undivided.
A. Ultimate cell of the primary ray of the leaf longer than the
other cells. 1 sp.:-T. longicoma A. Br.

B. Ultimate cell not longer. 4 sp.:- T. nidifica Leonh.; T.
Normaniana Ndst.; T. glomerata Leonh.; T. comosa Allen.

* Ann. Soc. Cientif. Argentina, xv. (1883) pp. 218-31. See Bot. Centralbl., xvi. (1883) p. 257.

Bull. Torrey Bot. Club, x. (1883) pp. 109-17 (6 pls.).

II. ACUTIFOLIA.-Corona persistent.

A. Indivisa. Sterile leaves undivided. 2 sp.:-T. prolifera
Leonh.; T. fimbriata Allen.

B. Divisa. Sterile leaves divided, usually into four terminal
leaflets. 5 sp.:-T. californica A. Br.; T. stipitata Allen;
T. intricata Leonh.; T. intertexta Allen; T. apiculata A. Br.

Fungi.

Rabenhorst's Cryptogamic Flora of Germany (Fungi).*—The publication of this important work has now advanced as far as the issue of the first division of the first volume, which is to comprise the Fungi, under the editorship of Dr. G. Winter. The present division includes the Schizomycetes, Saccharomycetes, and Basidiomycetes, all the species being described which are natives of Germany, Austria, and Switzerland.

Hysterophymes.t-H. Karsten applies this term to elementary organs which have been mistaken for independent living animal or vegetable organisms. In the present paper he explains the process by which he has developed them synthetically by constructing artificial cells of potato digested in a nutrient fluid of about 5 per cent. solution of sodium-ammonium phosphate with some potassium sulphate. In such cells albumen-cells may be seen to develope, and to multiply in a linear direction into the well-known bacterium, bacillus, and vibrio forms. The contents of these bacterioid organisms are coloured blue by iodine in a certain stage of development. On the addition of a solution of cane-sugar, the bacterium-cells formed within the closed potato-cells can be seen to increase and develope into the torula-form.

The

Cells of the kohl-rabi digested in the same nutrient fluid developed in the same way micrococci and bacteria; and, since they were taken from the bast-tissue, where there are no intercellular spaces, Karsten regarded any entrance of germs from without as impossible. author considers the experiments to prove that the so-called fermentcells arise from normally developed cell-sap vesicles, and that torulacells are only a stage of development of bacterium-cells or micrococci.

Graphiola.This exotic genus of Fungi is chiefly known from G. Phoenicis parasitic on Phoenix dactylifera and its varieties, as P. canariensis, also on Chamaerops humilis, and has been variously referred to the Myxomycetes, Uredineæ, and Pyrenomycetes. E. Fischer has undertaken a detailed examination of it, as well as of three other species, G. congesta, parasitic on Chamaerops palmetto, and G. disticha and compressa, the hosts of which are not known with certainty, and may belong to quite another genus.

The fructification of G. Phoenicis consists of small black elevations on both sides of the leaf of the date-palm, of a diameter about 1.5 mm.

*Rabenhorst, L., 'Kryptogamen-Flora von Deutschland, Oesterreich u. d. Schweiz. 1ter Band, Pilze, von G. Winter, Ite Abtheilung.' Leipzig, 1884. † Flora, lxvi. (1883) pp. 491-8.

Bot. Ztg., xli. (1883) pp. 745-56, 761-73, 777-88, 793-801 (1 pl.).

and a height of 0.5 mm. From the middle projects a yellow columnar body, about 2 mm. in height, composed of a number of vertical filiform bodies rising from its base, the space between them being completely filled by a mass of yellow spores. The fructification may be regarded as consisting of four parts, an outer peridium, an inner peridium, a spore-forming layer, and a tuft of hyphæ.

The outer peridium consists of a circular wall which spreads over the epidermis of the leaf of the host; it varies greatly in thickness, and consists of a number of branched hypha. This is bounded on the inside by a very delicate membrane, the inner peridium.

The hyphae which are destined to the formation of spores spring from the central part of the peridium; they are vertical to the surface of the leaf, and form a continuous palisade-like layer. The ends of these hyphæ are thicker than those of the hyphae which compose the sterile weft; they increase gradually in diameter upwards, attaining at the apex a thickness of about 3-4 μ. They are colourless, and filled with protoplasm which is either homogeneous or more refringent in some parts than others; they are septated tranversely into short cells, which at length swell into a spherical or ellipsoidal shape and become readily detached from one another. On the upper of these cells small protuberances now make their appearance, which gradually increase in size till they have attained that of the cells from which they spring; from three to six of them springing from one of the cells of the hyphæ. They are thin-walled and filled with protoplasm of varying refrangibility, which has passed into them from that of the hyphal cell, which eventually perishes. These bodies, which the author calls "spore-initials," produce the spores by one or more bipartitions of their contents. The ripe spores are usually found connected together in pairs; they are spherical or ellipsoidal, and about the same size as the initials, 3–6 in diameter; their membrane is usually moderately thick, colourless, and smooth.

μ

The tufts of sterile hyphæ spring, like the fertile ones, from the bottom of the fructification. They are slender, cylindrical, or irregularly prismatic bodies, from 7-18 μ in thickness, and strongly refringent. Each larger bundle consists of from 50 to 100 of such hyphæ; their membrane is much thicker and more refringent than that of the fertile hyphæ, but the refrangibility differs greatly in different parts of the same hyphæ. Their mode of formation is very similar to that of the fertile hyphae. As they develope they carry up with them the spores, which become attached to them, outside the outer peridium, where they are ready for dissemination.

The spores appear to retain their power of germination for a period of from three to four months. They germinate either directly with the formation of a septated germinating filament, or with the intervention of a single cylindrical sporidium produced from each spore. The germinating filaments grow to a length of 400 μ; their further development was not observed. There is no reason for believing that the genus has any heterocism or alternation of generations.

As regards the systematic position of Graphiola, the author does not agree with any of the views hitherto brought forward, but considers it

Ser. 2.-VOL. IV.

T

as most nearly allied to the Ustilagineæ; differing from them in its highly complex fructification. Until transitional forms have been found, he would erect it into a separate but closely allied family under the name Graphiolaceæ.

Pourridié of the Vine.*-R. Hartig believes that the cause of this disease is not as supposed, the "rhizomorph" of Agaricus melleus, but a different fungus, Dematophora necatrix n. sp., clearly distinguished from the former by its peculiar apical growth, the formation of sclerotioid agglomerations in the mycelium, and the form of the fructification. The mycelium is parasitic, and rapidly kills not only the vine, but many other trees which it attacks. Under favourable conditions, it forms great numbers of branched conidiophores; but since the perithecial form is at present unknown, the systematic position of the genus must remain at present undecided. Roesleria hypogaa ho regards as saprophytic, and a secondary cause only of the disease.

E. Prillieux, on the other hand, while agreeing with Hartig that the disease is not caused by Agaricus melleus, looks on Roesleria hypogœa as its true source. The coremium-like spores of this fungus he regards as ascospores, formed eight in each ascus.

Oospores of the Grape Mould.-E. Prillieux states that he has received from M. Fréchou of Nérac germinating oospores of Peronospora viticola. The germinating oospores produce at once a mycelial tube similar to that known in other species of Peronospora in which the germination of the oospores has been seen. This is an important step in our knowledge of the grape-mildew, since, inasmuch as the conidia produce zoospores, it had been supposed by some that the oospores would also produce zoospores, as is the case in the related genus Cystopus.

Pleospora gummipara.§-The fungus named by Beyerinck Coryneum gummiparum, connected with the flow of gum from woody trees, has now been found by C. A. J. A. Oudemans in the perithecial form, and been identified as belonging to the genus Pleospora, Sect. Eupleospora. As it cannot be identified with any species hitherto known, Oudemans calls it Pleospora gummipara, and describes the perithecial, pycnidial, and conidial forms.

Schizomycetes. -F. Neelsen gives a very useful epitome of the present state of our knowledge respecting the life-history and classification of this class of organisms, referring chiefly to the labours of Ehrenberg, Cohn, and Zopf. In the mode of investigation adopted by the last-named authority, and the theory of the pleomorphism of

* Hartig, R., 'Der Wurzelpilze des Weinstockes,' 18 pp., Berlin, 1883. Also Unters. aus d. Forstbot. Inst. München, iii. (1883) pp. 95-140; and SB. Bot. Ver. München, Jan. 10, 1883. See Bot. Centralbl., xvi. (1883) p. 208.

† Prillieux, E., 'La pourridié de la vigne, &c.,' 13 pp. (1 pl.), Paris, 1882. See Bot. Centralbl., xvi. (1883) p. 208.

Bull. Soc. Botan. France. Cf. Science, ii. (1883) p. 831.

§ Hedwigia, xxii. (1883) pp. 161-2.

Biol. Centralbl., iii. (1883) pp. 545-58.

the different organisms comprised in the class, he sees the promise of a fuller and more accurate knowledge in the future of their lifehistory.

Fæcal Bacteria.†-B. Bienstock has made a detailed examination of the bacteria found in human fæces under a great variety of circumstances. Those obtained from healthy men he found to belong exclusively to the group Bacillus, their spores having alone a sufficient power of resistance to the antiseptic action of the gastric fluid. Of this group five distinct forms were observed:-1 and 2. Two large forms, resembling B. subtilis in form and appearance, but differing in the mode of germination of the spores, and in not having the power of spontaneous motion. Although always present in the fæces, the author was unable to determine that these bacilli take any part in the fermentative processes of the intestinal canal; and they appeared to have no pathogenous properties. 3. A third form was characterized by its very slow growth and minute size; it acted pathogenetically on mice. 4 and 5. These two forms, invariably present in human fæces beyond the age of suckling, are of the greatest importance in the processes carried on in the digestive canal beyond the stomach. They were of different chemical properties, one bringing about decomposition of albumen, the other of carbohydrates; the second only was present in the fæces of infants fed only on milk. These forms alone have the power of decomposing albumen or carbohydrates; the one producing the well-known products of the decomposition of albuminoids, the other splitting up sugar into alcohol and lactic acid. The first produced no decomposing effect on saccharine solutions; the second none on solutions of albuminoids; though both multiplied freely. The other fæcal bacilli, and those obtained from the air, were also without the least effect. After cultivation for from twenty to forty generations these two forms still retained their power.

The author derives from these experiments the conclusion that the decomposition of albuminoids and carbohydrates in the intestinal canal is due in each case to one specific bacterial form, which brings about the decomposition without the assistance of any others.

Influence of Oxygen at high pressure on Bacillus anthracis. — J. Wosnessenski comes to the conclusion that Bert was right in regarding oxygen at very high pressures as being mortal to the protoplasm of Bacillus anthracis; but it is not to be supposed that a gradual augmentation in the pressure of the oxygen will gradually lead to the loss of vitality; till the pressure exceeds that of fifteen atmospheres of air the organism resists it better than it does oxygen at a normal pressure. The results obtained with increasing pressure vary considerably, according as the experiments are conducted with thick or thin layers; with the latter the influence of pressure is not marked; so that with them the result is the same as in Chaveau's experiments on Bacilli at a normal pressure, if a suitable temperature * See this Journal, iii. (1883) p. 688.

† Fortschritte der Medicin, i. (1883) p. 609. See Bot. Centralbl., xvi. (1883) p. 305. Comptes Rendus, xcviii. (1884) pp. 314–7.