or the more or less branched spores, composed of a varying number of cells. Excluding the pedicel-cell, the number of cells of which the spores are composed is usually five or six, though there may be a larger or smaller number. The separate spore-cells are often very beautiful in form, bearing a distant resemblance to the teleutospores of Puccinia coronata. The walls of the cells are usually more or less thickened, and often with considerable projections; though the thickening is often entirely wanting. They are cylindrical or ovoid in form, but with considerable variations, the length varying from 17 to 47 μ and the breadth from 15 to 21 μ; the terminal cell frequently differing very considerably from all the rest. A nucleus is present, but disappears before the commencement of germination. The spores germinate with great readiness, frequently even under the coverglass.

In larger patches the teleutospores are often accompanied also by the uredo-form. The uredospores also vary greatly in form, having perhaps an average diameter of about 26 p. They differ from those of species of Phragmidium which are often also found on the bramble, in the entire absence of paraphyses. They are probably identical with the bodies described by Fuckel as the acidial fruit of Phragmidium asperum. The uredo-form occurs abundantly on other parts of the plant besides the leaves.

Physoderma.-J. Schröter describes this genus of parasitic fungi as characterized by being altogether destitute of a mycelium; the spores forming directly abundant masses of spores within the parenchymatous cells of the host. Small colourless lumps of protoplasm gradually swell up into a spherical form, and become invested first with a simple, afterwards with a thick coat. This process resembles the formation of the resting-spores of Synchytrium; but Physoderma differs from Synchytrium by the spores being formed in the parenchymatous and not in the epidermal cells of the host, and by the resting-spores of Synchytrium having a firmer inner layer of the cell-wall, so that the outer layer bursts easily.

The author has observed for some years in the neighbourhood of Breslau a very remarkable species of Physoderma on Chenopodium glaucum, and apparently confined to this species, completely deforming it, and causing the stem and leaves to assume a reddish or yellow colour. In the coloured pustules which appear in the summer are found very large zoosporangia with orange-coloured contents. From the base of the zoosporangium a dense tuft of very fine branched hyphae penetrates into a parenchymatous cell of the host. Within this cell are formed very large zoospores endowed with very active motion, which pierce the tissue of the host and form new sporangia.

In the autumn are formed black pustules which contain the restingspores, which are formed by a process of conjugation. The zoospores attach themselves to a cell-wall; from this spot proceed very long and delicate threads of protoplasm bearing at their apices small spherical vesicles. On the summit of these vesicles is a tuft of delicate, * JB. Schles. Gesell. Vaterl. Cult., 1883, pp. 198–200. Ser. 2.-VOL. IV.

H

short, but often branched threads of protoplasm. Two of these cells appear to conjugate (though it would seem as if the act of conjugation has not been actually observed), the protoplasm passing from one into the other, which swells up greatly, being filled with protoplasm and drops of oil, and invested with a firm coat. The two conjugating cells place themselves one on the top of the other, and an open tubular communication is formed between them. The process presents the greatest resemblance to the formation of the spiny spores of Chytridiaceæ. Physoderma appears to be an intermediate form between the Chytridiaceae and Pythium and the Peronospores; and may also be related on the other hand to Cladochytrium.

Bacilli of Tubercle.*-According to Prof. Rindfleisch, tubercular bacilli are best stained by fuchsin soluble in alcohol, but not in water. Two or three drops of a concentrated solution in 2-3 cm. of anilin-oil water are sufficient. The staining is especially good at 40° C. The bacilli are uniformly stained if a few drops of fuchsin are added to a mixture of equal parts of alcohol, water, and nitric acid.

Microbia of Marine Fish.+-In pursuance of their researches on this subject, L. Olivier and C. Richet have ascertained beyond doubt the spontaneous motility of the microbes obtained from living fish, as distinguished from mere passive or brownian movements. Motile organisms were found in living specimens of Gadus luscus, which had been only twenty-four hours in an aquarium, in the cephalo-rachidean and peritoneal fluids; in the peritoneal fluid of a Blennius; in the blood of the heart of Gadus luscus, and in the peritoneal fluid of a whiting.

The

The absence of putrefaction in the lymph or blood of a fish does not prove the absence of living microbes; some of the examples named above remained for months without alteration. A good nutrient fluid for their culture was found to be infusion of beef. cephalo-rachidian fluid of a mud-fish was mixed with sterilized infusion of beef in one part of an exhausted tube. After three months no clouding appeared in it, but at the bottom was a minute whitish deposit. This contained mobile, short, flexuous bacilli, which were stained by methyl-violet.

Physiology and Morphology of Alcoholic Ferments.-C. E. Hansen describes the mode of formation of the ascospores of Saccharomyces, his description of which differs in several points from that of previous observers, especially Engel and Brefeld. He also contests van Tieghem's view that the formation of ascospores is a pathological phenomenon due to bacteria. He gives a detailed description

p. 18.

SB. Phys.-med. Gesell. Würzburg, 1882. See Bot. Centralbl., xvi. (1883) † Comptes Rendus, xcvii. (1883). Cf. this Journal, iii. (1883) pp. 402, Meddel. Carlsberg Lab., ii. (1883) 3 pls. (Danish with French resumé). See Bot. Centralbl., xv. (1883) p. 257. Cf. this Journal, ii. (1882) p. 234; iii. (1883) p. 232.

884.

of the characters by which the various species of Saccharomyces may be distinguished from one another. In all the species examined the ascospores were never developed below a minimum temperature of from 0.5° to 3° C., or above a temperature of about 37.5° C.

Hansen finds that some forms of Torula as well as of Saccharomyces can invert and also cause alcoholic fermentation; while others show the latter phenomenon only.

Alcoholic Ferments.-L. Bontroux employs as diagnostics of the species of fungus that induce fermentation the form of the vegetative cells, whether elongated or oval, whether they occur singly or in colonies, their fermenting activity, and their power of resisting acids and high temperatures. He describes as many as nineteen species of Saccharomyces, but some of them are forms of other fungi, as Oidium lactis, Dematium, &c.

Magnin's 'Bacteria.'t-The second edition of this book contains not only Cohn's accepted provisional classification of the Bacteria, but a general resumé of the latest labours in this difficult study, largely supplemented by the experimental observations of Dr. G. M. Sternberg, the translator. Scarcely any subject since the time of Jenner has attracted so much attention as the question of the proof of the infectiveness of certain of the bacteria. Opinions have fluctuated not only in connection with the difficulty of proof required, but also from the differences in the methods of experimenting. In some cases pure cultures have not been made use of, and in others the series of observations have not been of a sufficiently extended nature to determine correctness in the results. Dr. Sternberg is very critical in accepting some of the conclusions and statements made by others; and hence he has taken the precaution to lessen any objections that may be made against his own observations, which are therefore the more valuable and trustworthy. At the same time he avoids accepting the evidence where the subject is still under serious disWhen the experiments are of a positive nature, as in the virulence of his own saliva when injected into rabbits, he does not hesitate to join the ranks of those who insist upon the bacteria, bacilli, or micrococci being the cause of the malady induced, and not the sepsin or septic product produced by the microrganism, as has been insisted upon by some.

The fuller our knowledge of the role these invisible organisms play, the greater the facility of establishing the laws of hygiene and the means, if not of eradicating our common enemies, yet of lessening the virulence. Whether we are to accept Zopf's views of all forms being originated by development from the same organism; whether the common forms by transmission through various living organisms, or certain media, in themselves harmless or hurtful, obtain, increase, or lose their virulence; whether by the slow progress of evolution gathered

*Bull. Soc. Linn. Normandie, iii. (1883) 42 pp. See Bot. Centralbl., xv. (1883) p. 329.

·

† Magnin, Dr. A., Bacteria. Translated with additions by Dr. G. M. Sternberg, F.R.M.S.' 487 pp., 12 pls., and figs. 2nd ed., 8vo., New York, 1883.

in their course and transmission through different species of living bodies, modified properties have been acquired either in a single or several species, and whether by a selected reversal of the mode of life a reversion to harmlessness can be induced in the virulent forms, are questions of serious import that lie in the future. To those interested in the question of germicides (sporocides) and antiseptics, we may refer to an article by Dr. Miquel, the able observer at the Montsouris Observatory, Paris, who has largely extended the list, which is headed by biniodide of mercury.

Those who are in want of a subject for investigation may be strongly advised to cultivate an acquaintance with the pages of this valuable work, and add their own independent observations to the list of original articles of which there is a very copious bibliography brought down to a very late period. Dr. Sternberg can be congratulated on giving us a well illustrated and most readable addition to the literature of the bacteria with valuable information derived from his own careful experiments.

Lichenes.

Cephalodia of Lichens.†-K. B. J. Forssell proposes to confine the term Cephalodia to those structures which contain one or more algæ, the type of which differs from the normal gonidia of lichens, and which have been formed by the mutual action of hyphæ and algæ. Cephalodia have been at present observed in one hundred species of algæ, but belonging to only a few genera. They appear to occur chiefly in the Archilichenes. Those described in other families have mostly not been properly cephalodia, where the hyphae always obtain a stronger development from contact with the algae; as Peltigera canina, where the hyphæ serve to nourish the alga, or Solorinella asteriscus, where they are indifferent to one another.

The position of the cephalodia varies; they occur sometimes in the under, sometimes in the upper side of the thallus, sometimes on or in it; occasionally also in the protothallus. They usually form protuberances of a dark yellowish-red or dark red colour in the upper side of the thallus. When the cells of the algae which form cephalodia come into contact with the hyphæ the hyphae develope rapidly, involve the algal colony, and become copiously branched. The cells of the algae divide at the same time, thus increasing the size of the cephalodium by mutual symbiosis. Most cephalodia are formed by the mutual action of algae and of hyphae which belong to an already developed lichen-thallus (cephalodia vera). Among these the author distinguishes between cephalodia epigena or perigena, formed on the upper side of, or upon, the thallus, as in Peltidea aphtosa, Sphærophorus stereocauloides, and Stereocaulon ramulosum; and cephalodia hypogena, formed on the under side of the thallus. There are differences again among these. Sometimes (Solorina octospora) the cephalodium lies at the base of the medullary layer; sometimes

*La Semaine Médicale,' 30 Août, 1883.

+ Bihang till K. Svenska Vet. Akad. Handl., viii. (1883) 112 pp. (2 pls.). See Bot. Centralbl., xv. (1883) p. 330.

(S. saccatu and Lobaria) the alga penetrates into the medullary layer; or sometimes (S. crocea and bispora) it penetrates still higher into the thallus, and spreads into the yellowish-green gonidial layer, which is often replaced by it; or finally (Lobaria amplissima, Lecanora gelida, and Lecidea panæola) the gonidial and cortical layers are broken through, and the cephalodium emerges on the upper side of the thallus.

Under the name Pseudocephalodia (as distinguished from cephalodia vera) the author describes such as are formed in the protothallus by the germinating hyphae investing algal colonies of some other type than the normal gonidia of the lichen. They are but slightly united with the other parts of the thallus, and exhibit a tendency towards independent development. At present they have been observed in only a few lichens:-Solorina saccata var. spongiosa, Lecidea pallida, and probably in Lecanora hypnorum and Lecidea panæola. Intermediate forms also occur between the various kinds of cephalodia.

In some of the above-named species the author states that the pseudocephalodia develope in the same way as is described by Schwendener from the thallus of lichens, a point of considerable importance with regard to the Schwendenerian theory of the origin of lichens. In the true cephalodia we have in fact a double parasitism, or mutual symbiosis of algae and fungal hyphæ.

Lichens from the Philippines.-B. Stein describes a number of lichens forwarded by Dr. Schadenberg from Mindanao in the Philippines. Among them is a new genus, Dumoulinia, belonging to the Lecanorem, of which he gives the following diagnosis:-"Thallus crustaceus uniformis; apothecia lecanorina, superficialia, excipulo crasso cupulari; sporæ quaternæ, maximæ, hyalinæ, tetrablastæ."

Algæ.

Protoplasmic Continuity in the Florideæ.†-T. Hick has made an extensive series of observations on a large number of species belonging to the more important genera of Florideæ, with special reference to the question of protoplasmic continuity. He finds in all the species examined that there is such a continuity, and that of the clearest and most definite character. In the simpler filamentous types, such as Petrocelis cruenta and Callithamnion Rothii, the protoplasm of each cell is united with the protoplasm of contiguous cells by means of a fine protoplasmic thread. This occurs throughout the whole plant. In the more complex types, such as Callithamnion roseum, arbuscula, and tetragonum, the arrangements for continuity are of a more elaborate character. The contents of the axial cells are not only united with one another, but also with those of the cortical cells, however numerous these may be. The cortical cells also display continuity inter se. Ptilota elegans is a most instructive form, as here the connective threads may be easily traced from the tips of the ultimate branchlets to the base of the stipes of the frond. As the

JB. Schles. Gesell. Vaterl. Cult., 1883, pp. 227-34.

† Proc. Brit. Assoc. Adv. Sci., 1883. Cf. Nature, xxix. (1883) p. 581.