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larger expanse of scarlet on the head and neck. The habitat is the southeast.

Another species from southeast New Guinea, along the Fly River, differs from the first named chiefly in having a glossy black upper surface instead of blue. It is known as D. rubrigulare.

Smaller and more plainly colored is D. pectorale, whose leading tints are olive-green above, yellow on head and rump, no scarlet whatever excepting on the upper breast, the remaining under parts and tail-coverts light yellow, exclusive of the whitish under wing-coverts.

From the Bay of Gielvink comes D. gielvinkianum or mafoorense, of an olive color above glossed with steel-blue. Here again a shade of red appears on the crown, rump, upper tailcoverts and breast. The under surface is a yellowish-white bordered along the sides with olivaceous. A more brightly tinted variety is named D. jobiense.

The genus Oreocharis of the Dicæidæ, represented by one species, is peculiar to New Guinea; this is Oreocharis arfaki, collected by Mr. Goldie in the Astralobe Mountains. This is a larger bird by two inches than those of an allied kind just considered. The color above is dissimilar, viz.: an olivaceous, somewhat glossed. The dusky wings, however, are touched with green and yellow on some of the feathers. So, too, the tail above. Crown of the head and sides glossy black, melting into bottle-green on the neck. About the eye are dashes of the brightest corn-yellow. This is the color also of all the under parts, excepting the black throat. The under wings are paler, with black touches. A reddish stripe may be seen in the gold ground of the under parts.

Urocharis longicauda is likewise the sole species of the genus Urocharis, and occupies the same region of the Arfak Mountains. Above the general color is a shining black, the only exceptions being the rump, which is gray, and the tail, where on the outer feathers a long spot is visible. The side face is olivaceous; this is the color on the under body mingled with pale yellow. The female is larger by more than half an inch, and is a smooth olive-green. Length, about five inches. The tail nearly half this figure.

The genus Melanocharis comprises four species, all from New Guinea and its islands. These are not very dissimilar in size or coloration. The best known, well named M. nigra, is a glossy black above of a bluish cast. Beneath the principal tint is olivaceous, passing into pale yellow on the abdomen. The under wing-coverts are white. Total length, nearly five inches. Another genus of the same family, consisting of but a single species, is Pristorhamphus veroteri. A larger bird this by an inch, with rich, velvety black plumage above, emanating pale green. Underneath a bluish tint. Besides, some spots of white on the tail, apparent when the bird is flying, but concealed at other times; there are white plumes, very soft and delicate, waving on either flank. The female is equipped with these same adornments, but is of dimmer coloring, mainly olivaceous. Habitat, the Arfak Mountains.

Less by more than an inch is Rhamphocharis crassirostris, the sole member of its genus. An olive-green bird above with dusky brown wing- and tail-coverts, and blackish tail. Below the body is a pearl-gray with a yellow wash. The female is of larger size, olive-brown above, but differing from the male in being rather more varied in neutral colors, yellow and white spots or dots appearing on the dull surface of wings, tail and back. The under parts are of a soiled white, specked with yellow and brown. The bill is not noticeably larger than that of other species.

THE BACTERIAL DISEASES OF PLANTS:

A CRITICAL REVIEW OF THE PRESENT STATE OF OUR KNOWLEDGE.

BY ERWIN F. SMITH.

II.

I. THE BEET (BETA VULGARIS L.).

1. THE BACTERIOSIS OF FODDER BEETS (1891).

(I) THE DISEASE.

(1) Author, Title of Paper, Place of Publication, etc.-This disease was first described by Dr. Ernst Kramer, Privat Docent

in the technical high school in Graz. His paper entitled (23) Die Bacteriosis der Runkelrübe (Beta vulgaris L.), eine neue Krankheit derselben, was published in Oesterreichisches Landwirtschaftliches Centralblatt, Jahrg. I, Heft 2, pp. 30 to 36, and Heft 3, pp. 40 to 41. Graz, 1891.

(2) Geographical Distribution.-The disease prevailed extensively in 1890 in the Eltzischen earldom in Vukovar, Slavonia. (3) Symptoms.-The beet roots were said to be shrivelled and to contain comparatively little sap. The whole of the affected roots began to change to dark brown soon after harvest. On cutting them open dark brown spots were visible. During the winter the disease spread in the beet cellars to apparently sound beets, in spite of the fact that all roots showing any signs of disease were thrown out and destroyed at the time of storage. Roots in which the disease was well advanced showed a gummy ooze which appeared to be infectious to sound beets. Cattle fed with slightly infected roots were attacked with severe bloating and obstinate constipation, and in one case death ensued. Such was the account forwarded to Dr. Kramer along with samples of the diseased beets. There is no record of the symptoms of this disease as it occurs in the field. The diseased beets received by Dr. Kramer were shrunken and in some places were soft under the epidermis. From these soft places there oozed a slimy brownish fluid, which stuck to the fingers, but was without characteristic smell or taste. Brown or dark brown spots more or less softened, and of various sizes, were visible on cross-sections of roots not too badly infected. The inside of those specimens which were badly attacked was, however, almost entirely brown, and in parts the parenchyma was wholly destroyed, giving place to a slimy, sticky, gum-like, brown-colored, strongly acid, odorless fluid. The destruction of the tissues proceeded so far in some parts of the root that, finally, only the vascular bundles remained. The beets attacked by this disease yielded no characteristic odor, and they only began to smell bad in the last stages of the disease after rotting had set in.

(4) Pathological Histology.-An examination of thin sections, made through a brown spot, showed that the cells of this

parenchyma contained tiny roundish or ellipsoidal shining bodies, which were of various sizes, and either scattered about in the cells or united into groups. The individual particles showed not rarely a tremulous motion. When such a thin section was fixed to a cover glass by passing it three times through the flame, and was then stained with gentian violet, these bodies became a beautiful blue, and their bacterium-like form could be made out more clearly. In the parts of the root which had already become slimy great numbers of bacteria were to be seen in the gum-like fluid, together with loosened cells, plasma, and fragments of cell membranes.

(5) Direct Infection Experiments.-When a little of the soft, slimy mass was lifted on a sterile platinum needle and spread on a sterile [steamed ?] section taken from an apparently sound beet, the surface of the latter was covered within forty-eight hours with a slimy, brown, gum-like, acid layer, which consisted of a mass of those bacteria previously found in the diseased beets. Sections cut out of diseased beets with sterile knives and placed on fresh, unsterilized sections from sound beets, and kept in a moist chamber at 24° C., caused the latter to become affected. The infected spots browned and softened, and in the tissues bacteria appeared, which were just like those occurring in the diseased beets. A slimy layer also formed on the sterile cut surface of carrots when a slight quantity of the slimy ooze from the beets was spread over it.

"This preliminary investigation indicated that most likely in this case we have to do with a disease caused by bacteria. Positive proof, however, is not thereby afforded. To accomplish this experimentally it is absolutely necessary to isolate the bacteria occurring in the diseased beets, to cultivate them pure, and then to inoculate the pure cultures into sound living beets. If then as a result of the infection the previously healthy beet should become diseased with the before-mentioned symptoms, and the originally inoculated bacteria should appear once more in the tissues, then there would be no doubt about this being a bacteriosis of the beet."

Clearly this man knew exactly what he had to do.

(II) THE ORGANISM.-This is described as a bacillus, but not named.

(1.) Pathogenesis.

(A) Yes.

(B) Yes. Rather easy.

(C) No. These inoculations led to no satisfactory result, and had to be abandoned, because no suitable beet material was at the experimenter's disposal.

(D) No.

Conclusion.-Pathogenic nature rendered probable. The reason for this judgment in opposition to the above statements will be found in the following paragraph.

While Dr. Kramer was not able to secure infections, owing probably to the unfavorable conditions under which he worked, he hit upon an ingenious method of indirect proof, viz., the development in pure cultures of the same gum which is formed naturally in the diseased beets. His method was as follows: The softened or liquefied parts of the diseased beets were cut out, crushed and heated on a water bath, with the addition of a small quantity of milk of lime. The fluid was then decanted, and the remaining mass of beet squeezed as dry as possible and the two fluids mixed, filtered, and carbon dioxid passed into the filtrate for the removal of the somewhat superfluous lime. The fluid was again filtered and concentrated on the water bath. The fluid was now rendered acid by the addition of some drops. of acetic acid, and a white, tough, gum-like substance was precipitated out of it by the addition of 96 per cent. alcohol. To obtain it in a pure condition this substance was repeatedly dissolved in water and reprecipitated by alcohol. The same substance was obtained directly from the gummy ooze of the diseased beets by dissolving it in water, heating, filtering, concentrating on the water bath, and precipitating with alcohol. In this case also the precipitate was a white, tough, gum-like substance. Both of these precipitates were tested chemically with the following results. Mixed with soda-lime and heated in a test tube there was no formation of ammonia, a proof that the substance was free from nitrogen. Boiled with orcin and hydrochloric acid it gave the well-known gum reaction, men

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