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the same extent as the sheep or deer. Out on the plainsonly four or five are seen together even now. Before the

advent of the white man with his flocks and herds the

kangaroo only ranged in the neighbourhood of permanentwater where the land was firm enough to support him. No

doubt, when he was driven out on the rotten ground by dogor man, the great bird-like claw on his hind leg affordeda better support than the hoof of the sheep or bullock.

The great strength capable of being exerted in the hindleg of the kangaroo would also enable him to extricatehimself from a bog more easily than animals of a highertype of development. His short forepaws would be usefulin ‘ clawing’ himself along over rotten ground. But

kangaroos do not follow each other and make tracks,and this is how the sedimentary deposits of the Ganges, theNile, the Amazon, the Mississippi, and other deltas havebeen principally consolidated and compacted." The

"rottenness" of the soil of the Australian plains in the earlydays of colonisation is shown by such facts as that a

walking-stick could be thrust its full length into what lookedlike solid earth without using any special effort, a horse orbullock sunk up to his belly in the soil, and a full-woolledsheep could not extricate itself but had to be rescued. Whilethis condition of things lasted the land was not flooded,as the waters sank into the porous earth and left theirsediment resting lightly on the top. It is believed thatthese waters escape somewhere to the ocean, and in the

Mount Gambier district water has been found running in underground channels at the rate of four or five miles anhour. Irrigation is alone required to make the Australianplains productive. "The plains of Australia," concludes Mr.Boxall, "are singularly alike, and if the plains of Northernand Western Australia can be consolidated by the tramplingof stock, as I believe those of the eastern districts have

been, the time is not far distant when the word ’desert’may be wiped off the map of Australia, and the true

character of its vast plains become more generally understoodand appreciated." -

"PSEUDO-ACTINOMYCOSIS."

IN the Russian Archives of Pathology, Clinical Medicineand Bacteriology Dr. T. G. Savchenko relates an interestingcase of what, clinically speaking, was actinomycosis, butwhich differed from ordinary forms of this affection in itspathological course. Dr. Savchenko has seen several casesin Kieff and all except this one were due to fungi as ordi-narily described. The patient was a peasant thirty yearsof age who had passed through his period of military serviceand had afterwards worked in the fields, being, in fact, inrobust health until his illness began, which was about

May, 1893, when he began to feel pain in his back. Sub-

sequently a tumour appeared on the left side of the chest,which ultimately burst the skin and discharged large quan-tities of pus. When admitted into the St. Cyril Hospital,Kieff, in September, 1893, the tumour-which extended

. from the sternum to the left axilla and from the clavicle tothe fifth intercostal space-was firm and covered by bluish-red skin. There were four sinuses with everted discoloured

edges, from which pus with a peculiar disagreeable smellwas discharged, together with a large number of whitishgranules. There was but little cough and no sputum. The

lungs gave no indication of disease and the urine was freefrom albumin and casts. New abscesses continued to formin the part affected and more than one operation was per-formed, but by April, 1895, the patient was dischargedpractically cured. The unpleasant-smelling pus was presentthroughout the whole course of the disease. It was

significant, too, that the granulations occupying the

sinuses were of a brown colour, very easily broken

down, and contained a large quantity of blood. The

chief interest of the case lies in the microscopicand bacteriological examination. When examined with low

powers the granules did not look unlike those of actino-mycosis, but when high powers were used it was seen that

they were totally distinct, being, in fact, zoogloea made upof numbers of bacteria differing from one another in size..Bacilli were also contained in the pus apart from the granules,some being free and others within leucocytes. The bacteriawere all stained by aniline colours, but not by the Gram stain.When isolated they were found to be absolutely anaerobicand never formed colonies on the surface of nutrient media.In glycerin jelly isolated granules were formed consistingof bacilli. A rabbit inoculated with a pure culture always.presented an abscess in which the same bacilli, sometimesmassed in zoogloea, were found, and always had the specificsmell which was noticed in the patient and which was alwayspresent in the cultures. Dr. Savchenko proposes for this.affection the term bacillary pseudo-actinomycosis."

IMPROVEMENTS IN THE NEW PHOTOGRAPHY.

WE mentioned three weeks ago some experiments which wemade with some sensitised metal plates submitted to usby Mr. Strauss Collin of Bush-lane House, Cannon-street,E.C. We have since obtained excellent results with these-in THE LANCET Laboratory. They are developed in theordinary way, using" rodinal " preferably as a developer,.and fixed in the hyposulphite bath. Very thorough washingis the next step. The image which first appears on develop-ing vanishes in the hyposulphite solution. When the plate,.after washing, is, however, placed in a solution of perchlo-ride of mercury the image reappears with great distinctness.and with excellent detail. For medical work the employ-ment of these plates offers undoubted advantages. Thus

the thin sheeting upon which the sensitised film is spreadmay be adapted to any shape, and, unlike glass plates, is

not easily fractured, so that it may be placed underthe body of a patient without risk of breaking. Moreover,as will be gathered from the foregoing description of the

process of development, a positive not unlike a ferrotype is.at once obtained. The "tones" are good and the platesfairly rapid, the exposure we adopted in the case of theankle being three minutes.

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EXCITABILITY OF NERVES AFTER SECTION.

IN the Archives de Physiologie a paper by Arloing recentlyappeared in which were detailed a number of importantexperiments in reference to the duration of the excitability of’the peripheral end of a cut nerve in warm-blooded animals.An abstract of this paper was published in the last numberof the -LVemrologise7tes Centralblatt. Waller and Ranvier

showed long ago that in pigeons and rodents excitabilityrapidly disappeared-in the course of two or three days.Arloing has investigated this variation very carefully, andaccording to his experiments the excitability of the peri--pheral end of the cut facial nerves in ungulates dis-

appears in from eight to ten days. Microscopical examina-tion of the nerve at this period shows disintegration ofthe myelin into drops in places, while at other partsthe myelin is intact or shows only some irregularity of its

borders. The individual differences are very striking.Thus in one case the peripheral end of the facial nerve

was found excitable thirty days after section. In the sameindividual also the different nerves showed different con-

ditions. Thus in a dog the facial nerve was excitable at itsperipheral end five days after section, while at this time themedian nerve was not excitable. As a rule the excitabilityof the cranial nerves took longer to disappear than that ofthe spinal nerves. In the same nerves also the different.bundles lost their excitability at different periods. For