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The Phascums are among the most minute of mosses. illustration of P. serratum shows it in an advanced stage of maturity, and very greatly magnified, the confervoid shoot developed into a long, irregularly-toothed leaf. The network of the leaf appearing only like alternate lines, light and dark, a little higher magnifying power, or a little more light thrown on a single, separated leaf, would show the beautiful reticulation. The species is not unfrequent upon sandy shaded banks, though Hooker says of the whole tribe of Phascums, that they are more frequently met with in the southern, than in the northern parts of Great Britain.

Another and still more common species is P. muticum, or common dwarf earth-moss, found on moist banks and fallows, and fruiting at the same season as P. serratum, viz., in autumn and spring. The leaves in this species are widely ovateacuminate, nerved, very concave, so as sometimes to appear almost hemispherical, the two innermost larger than the rest, erect, minutely toothed above, and all connivent, embracing the immersed fruit, a tuft of this moss looking like a cluster of minute bulbs.

When mature, this species is without the converva-like shoots so conspicuous in P. serratum. The capsule is round,

of a reddish colour, thick texture, and is seated on a short, thick pedicel; the columella distinct; calyptra very small, erect, campanulate, covering only the apex of the capsule; spores small, smooth, and round. Barren flower gemmiform at the base of the fertile; antheridia without paraphyses.

Phascum Floerkeanum, or Floerke's dwarf earth-moss, also fruits in September and November. It grows upon clayey or chalky soil, but is less readily discovered than its allies, not merely from its minuteness, being only about one-twentieth of an inch in height, but also from the absence of greenness, its colour being brownish, and scarcely different from that of the soil on which it grows. It is found in scattered patches, has scarcely any stem, and few, but crowded leaves, the lower ones very small and nerveless, the upper ones larger, with an excurrent nerve, concave, slightly recurved at the point, and with a reflexed margin. The areola small and rhomboid.

The capsule, which is entirely covered by the leaves, is of a reddish-brown, roundish-ovate in shape, with a thick blunt beak or point, one-third of its own length, and seated on a very short, thick pedicel. The calyptra is sub-conical, sometimes, but not often, cloven on one side. The barren flower is axillary, and the antheridia naked; the spores small, pale, and numerous.

Most beautiful is the foliage of P. cohærens, fruiting in the winter, and also bearing an immersed sub-sessile capsule. The leaves are erect, carinate, ovate-lanceolate, usually nerved to the apex; but sometimes the nerve is wanting, or incomplete: the areola of the leaf, however, as seen through the microscope, present the appearance of a symmetrical network, and all the upper part of the leaf is serrated.

Among the larger members of the family are P. alternifolium and P. multicapsulare, both somewhat rare, or overlooked, and both fruiting in the spring.

Other members of the family have exserted capsules, as P. rectum, P. bryoides, P. nitidum, and P. curvicollum. Of these, P. rectum, or the Straight-necked earth-moss, bears its fruit in winter, and on a straight elongated pedicel. P. curvicollum, or the Swan-necked earth-moss, has an exserted cernuous* capsule on a curved elongated pedicel. P. nitidum, or Delicate earth-moss, grows on moist banks, or on the dried sediment of shallow pools; the height of its stem one to six lines, erect, simple or branched, with new growths, like supplementary extensions of the stem, immediately below the fertile flower, each of these extensions bearing another fertile flower, and in time another, so that sometimes several capsules in different stages may be found at intervals along the stem, giving it the appearance of being pleurocarpous, or lateral * Bending forward; from cerneo, to stoop with the face forward.

fruited, though the fruit is really terminal. The capsule is of a pale brown, of fragile texture, elliptical, with a short, oblique point. Inflorescence monoicous; fruit, autumn and spring.

DISEASE GENERATED BY INFUSORIA.

M. DAVAINE communicated, a short while since, to the French Academy, a paper on the discovery of infusoria, belonging to the genus Bacterium, in the blood of animals afflicted with a disease of the spleen (sang de rate). Following this, came another paper by M. Signol, to the effect that these infusoria had been noticed by Fuchs in 1848, and also by M. Brauell of Dorpat, and by M. Pollender. He likewise stated that they had been described by M. Delafond, in the Bulletin des Séances de la Société des Veterinaires, in 1860. M. Signol affirms that they appear in horses suffering from typhoid disorders, influenza, etc.; and he adduces a case of their appearance in the blood of a horse that died of gangrene which supervened upon a wound from a pair of scissors. He sums up his conclusions as follows::

(1) "That bacteriums are not peculiar to the blood of animals suffering from spleen disease (sang de rate). (2) That blood containing them will inoculate and give rise to abundance of the same creatures in the blood of other animals so treated. (3) That the presence of fat in the tissues and fluids of the economy, the obese state of the afflicted creatures, the resemblance noted by M. Davaine between these bacteriums and those occurring in butyric fermentation, establishes a presumption that fat plays an important part in these phenomenon."

M. Davaine resumed the subject in a second communication, which contains the following remarks:--

"In fourteen inoculations of rabbits made with fresh blood infected with bacteriums, símilar organisms were reproduced and death supervened. In many cases the infusoria were observed two, four, and five hours before the death of the inoculated animal. In several of these cases blood taken from the animals while still alive transmitted the malady and determined its death with bacterium infection.

"The bacteriums are developed in the blood, and not in any special organ. When by persevering search any of these bodies are discovered at the beginning of the infection, they

* See "Pasteur on Putrefaction," INTELLECTUAL OBSERVER, Sept. 1863. Comptes Rendus, 10th August, 1863.

are very short as well as very scarce, but they will soon be seen to multiply and grow rapidly, their complete evolution only requiring a few hours for its accomplishment. A rabbit, the blood of which merely exhibited a few bacteriums, from four to six thousandths of a millimeter in length, died at the end of four hours, and its blood, which was examined immediately afterwards, contained a considerable number of bacteriums, some of which, larger than any I had previously seen, reached the five-hundredth of a millimeter in length.

"In some animals the bacteriums are generally found larger than in others, but not presenting any other difference. In such cases their number was usually less. The length

which the filaments sometimes acquired suggests their classification among the Confervæ ; but I omit, for the moment, the discussion of this question, as it has little importance in the present inquiry.

"The number of the bacteriums varies much between one animal and another. After my first inoculations this number decreased very rapidly, and they became eight or ten times less than the blood corpuscles. This led me to believe that their propagating power dwindled in rabbits, but I was afterwards convinced that such was not the case, as in a series of eleven individuals, one inoculating the other in succession, the blood of the tenth contained myriads of bacteriums like that of the first. I can only explain these variations by the changes in atmospheric temperature which occurred during my experi

ments.

"When the infected animal dies the bacteriums cease to multiply or grow, and in blood removed from its vessels they become destroyed or transformed. The loss of their primitive aspect is accompanied by loss of the power of propagating themselves in a living animal. Two inoculations effected, one with sheep's blood kept for eight days, the other with rabbit's blood kept six days, neither occasioned the spleen disease nor the formation of bacteriums.

"When fresh blood is rapidly dried in free air, the bacteriums preserve the faculty of inoculation, as I found in many experiments. The dried blood can sustain a temperature of 95 to 100' (C.) without this faculty being destroyed.

"Some fresh blood was enclosed in a tube and kept for ten minutes in water in ebullition. This blood being afterwards introduced under the skin of a rabbit, led to its decease, with formation of bacteriums in thirty-one hours. Cooking is therefore insufficient to destroy their vitality.

"In fourteen rabbits the mean duration of life after inoculation was forty hours; the shortest period being twenty-eight hours, and the longest sixty-seven. The duration was longer

in adults and old animals than in young ones. During this period the bacteriums are slow to appear, but from the moment of their occurrence the animal has but a short time to live. The longest interval that I have observed between the appearance of the bacteriums and the death of the inoculated animals was five hours, thus the mean length of the incubation period is thirty-five hours.

"During the incubation period the animal loses nothing in power or agility; it is only in the last two hours, when the bacteriums exist in notable quantity, that the rabbit ceases to eat or to run. It then lies on its belly, grows rapidly weak, and dies without any special symptom. Sometimes, however, death is preceded by slight convulsive movements."

M. Davaine goes on to say that autopsy shows a healthy condition of the large organs, but the heart and large vessels are distended by very cohesive clots. Coagulation of the blood is thus the only apparent cause of death. During life the microscope shows this coagulative action, as the increase of the bacterium is found to be associated with a viscosity of the red globules, and a tendency for them to adhere together. The large organs only contain the bacteriums as a consequence of their vascularity, and the spleen, which is very vascular, appears the focus of their reproduction.

M. Davaine concludes this paper by observing that experience shows the appearance of bacteriums in the blood precedes the phenomena of disease, and it is therefore natural to refer the latter to the former, which enjoy an individual vitality, and propagate themselves after the manner of living beings. While the blood only contains them in the germ; while their development is not effectuated, the morbid phenomena are not produced. But if the question is examined from another point of view, it seems probable that blood in which they have not made their appearance would be incapable of propagating them in a new animal, that is to say, that during the period of incubation they could not be sown, and the spleen disease (sang de rate) could not be communicated by inoculation.

In a third paper M. Davaine states that he inoculated a healthy and vigorous rabbit with three or four drops of blood from another rabbit infested with bacteriums, but still living. Forty-six hours after the inoculation, being six hours beyond the mean time of death, he examined the inoculated rabbit without finding any bacteriums. He then took from its ear twelve to fifteen drops of blood, that were injected into the subcutaneous tissue of a third rabbit, about two-and-a-half months old. Nine hours after this the rabbit first inoculated was found to contain a quantity of bacteriums, and some blood from its ear was introduced into the sub-cutaneous tissue of a fourth