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On June 8 this was the subject of a StephenPaget lecture to the Research Defence Society byProf. P. A. BUXTON, F.R.S., who has gained first-handexperience of the work being done on the tsetsein the last three years by making extensive tours ofthe fly belts in east and west Africa on behalf of theColonial Office. BuxTON emphasised the size of theproblem by pointing out that the territory heldby the tsetse, some 4,500,000 square miles, is abouttwice the area of the U.S.A. or about seventy-five timesthat of Great Britain. The beginnings of knowledgeabout the fly and its disease-carrying habits are foundin observations of the early explorers. LIVINGSTONEhimself, in 1858, made a startlingly accurate guessabout the possible carriage of a noxious organism bythe tsetse, before the transmission of pathogens byinsects was recognised. The discoveries of the carriageof the trypanosome diseases of animals and man weremade by BRUCE and others about the turn of thecentury. But it was not until the inter-war period thata systematic study of the detailed habits and distri-bution of the various species of glossina was begunby SWYNNERTON and his associates. One of theearliest methods of study was the " fly round," aperiodic peregrination with a bait animal, to countthe numbers of tsetse coming to feed on it. Usefulinformation about fly density in different areas andat different times of year was obtained; but it was

only of a relative nature. Subsequently, JACKSONintroduced a method of releasing marked flies and

attempting to recapture them at intervals. From the

proportions of marked flies in the subsequent captures,after correction, the absolute numbers of flies in agiven area could be estimated. Concurrently withwork on the flies, research progressed on the trypano-somes and the intricate problems of infection of thefly and the cycle in that host.

Several methods of fly control have been adoptedon the basis of the research findings. One of the mostimportant results .was a good knowledge of the

particular habitats of different tsetses. These breedingand resting sites, which Bux2orT illustrated in a

coloured film, are often very sharp and specificto certain areas (e.g., strips along rivers or streambanks) or even to certain types of tree and scrub.It is therefore possible to exclude some flies byselective clearing ; sometimes the work merely entailsfelling a very small proportion of vegetation toeliminate flies from a large area. The fly-countsand the knowledge of the slow breeding habits ofthe insect have suggested another method of elimina-tion : by simple repeated hand catching. This hasbeen found effective and practical in some isolatedsites. A third and highly valuable method of attackingtsetse is by colonisation. The agricultural and otheractivities of human settlers above a certain densitvwill drive away the flies and eventually render thearea safe for cattle. If °colonisation is left to theAfrican he will do it patchily, engulfing neglectedareas of fly belt because he does not consider themfertile enough. ’ This results in maximum contactbetween the fly and man and his animals and leads tcfailure. Government settlement schemes are therefore

necessary ; schemes which need careful considerationof tribal customs, agricultural needs, and a hostof other problems unrelated to the tsetse. Amost successful venture of this kind has been

carried out at Anchau in Northern Nigeria(700 sq. miles).Then there is the method of fly elimination which

has aroused misgivings in naturalists and big-gamehunters-the systematic destruction of large gamein the required area. This method is clearly effective,for some important tsetses, such as G. morsitans,disappear with the game ; and the game animalsare the reservoir of trypanosome infection for domesticcattle. The practicability of game clearance hasbeen demonstrated in Southern Rhodesia, where thelargest tsetse-fly clearance in Africa has been achievedby this method. Modern insecticides have been

brought into use against the tsetse fly and large-scaleexperiments are still in progress. Perhaps the air-

plane spraying of D.D.T. or ga:mma-B.H.c. smokes will befound a useful aid in clearing important or localisedbreeding sites, but the method is far too expensive tobe applied to the main problem. The attack on the

trypanosome which causes human disease has con-tinued, and curative and prophylactic drugs are beingwidely used. The prolonged suppression of the

parasite which can be achieved suggests that, if the

drugs are given to a sufficiently high proportionof the population, sleeping sickness can be stampedout of some areas by this means alone. BuxTONforesaw that some of these numerous measures

now considered promising will perhaps eventuallybe dropped. But the complexity of the problemseems to demand complex remedies.

Bacteriological NomenclatureWHAT’S in a name ? So far as bacteria are con-

cerned there may be much or little. Scientific namesare now given to bacteria with the intention of makingclear the relationship of one organism with another.This was not always so ; in the last century everyrod-shaped organism was called by the generic nameBacillus, which in no way indicated its systematicposition. In 1936, at the second congress of the

International Association of Microbiologists, the

generic name Bacillus was reserved for the aerobicspore-bearing group. But even now some medicalstudents are taught the anachronistic nomenclatureof the Bacillus era, and medical journals (ourselvesincluded) still often allow it to invade their columns.It is time that medical bacteriologists, especiallyteachers, abandoned their names-don’t-matter attitudeand learned a little of what systematists throughoutthe world are trying to do to make the name

something more than a label.The modern English usage, as exemplified by

Topley and Wilson’s Principles of Bacteriology andImmunity, is based on an interim report of a com-mittee of the Society of American Bacteriologists.In America, nomenclature has evolved from the finalreport of the same committee, the different stagesbeing represented by successive editions of Bergey’sManual of Determinative Bacteriology. Topley andWilson’s classification may be described as a con-servative application to bacteria of the binomialsystem of nomenclature. In the first edition mostof the gram-negative rod-shaped bacteria, chiefly ofintestinal origin, were placed in an unwieldy genusBacterium, but the latest edition (1946) recognisesthe separation of the typhoid-food-poisoning groupas the genus Salmonella and the dysentery bacilli as

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Shigella. Other coliforms and related organismsremain as Bacterium, though groups within the genusare recognised without being accorded generic rank.Thus Escherichia, Aerobacter, Citrobacter, Eberthella,Erwinia, Alcaligenes, and Klebsiella, to mention someof the generic names found in American literature,are not used, and sound arguments against their

adoption are given. The separation of some of theseso-called genera-Klebsiella from Aerobacter, for

example-is so ill defined that the site of origin,above or below the umbilicus, is often the decidingfactor. British bacteriologists may think that someof these groups deserve generic rank but believe thatrecognition would be premature until we know betterhow to distinguish them. The sixth edition of Bergey’sManual is not yet obtainable in this country, butearlier editions have each involved shifting manyspecies from one genus to another, and we are toldthat the American Type Culture Collection, whichadheres to Bergey’s nomenclature, has had to changethe names of nearly all its cultures to conform withthe 1948 edition of - the Manual. Unstable nomen-clature of this kind does not appeal to bacteriologistshere, and the only consistent users of Bergey namesare biochemists, who must abide by the editorial

policy of the Biochemical Journal.Names of species present a different problem ;

confusion from synonyms (different names for the sameorganism) is greater than from homonyms (the samename given to different organisms). Some bacteriamasquerade under many names ; the organismsthemselves may be well known (Pseudomonas pyo-cyanea, Ps. aeruginosa) and the synonymy easilychecked, or they may be less common (Bacilluspolymyxa, B. aerosporus) when the multiple nameswill be more confusing. In many examples of

synonymy the description appended to the first andlegitimate specific name was vague or insufficient fora subsequent worker to identify the organism ; inothers the second or subsequent name was bestowedbecause the author either did not know of the earliername, or thought that the organisms were sufficientlydifferent to justify distinct specific names. Homonymyis uncommon ; an example is Actinomyces bovis, whichhas been applied to both an aerobic and an anaerobicspecies, the former being regarded as a harmless

saprophyte, the latter as the probable cause of actino-mycosis. To avoid confusion the specific name

israelii has been proposed for the anaerobe.What can be done to put matters straight ?

Bacteriologists themselves, through the InternationalAssociation of Microbiologists, have drawn up a codegoverning the acceptance of names already given andrules and recommendations for new names. This

Bacteriological Code was approved by the fourth

congress of the association at Copenhagen in 1947,and has recently been published.l The associationalso established a Nomenclature Committee whichfrom its members elected a judicial commission togive " opinions " on the validity of proposed namesof genera and species. The commission will draw uplists of proposed names so that homonyms may beavoided in choosing new names. Some names, invalidby strict application of the rules but sanctioned bycommon usage, may be allowed to stand and will be

1. J. Bact. 1948, 55, 287.

published by the commission as nomina conservanda; ;others will appear on lists of nomina rejicienda. It is

unlikely that these opinions and lists will be availablebefore further confusion has arisen ; the Nomen-clature Committee was first appointed in 1930 and sofar only two generic names (Bacillus and Salmonella)have been approved. The committee has set upsubcommittees to consider the family Enterobacteraceœ(Salmonella, Shigella, Bacterium) and the genusStreptococcus ; these subcommittees have to tackle

thorny-problems and will do well if they can produceschemes acceptable to the differing viewpoints of

bacteriologists. What, then, of the immediate future ? American workers, with a new edition of Bergey’sManual as a stimulus, will presumably use new com-binations and entirely new names, based on therecommendations of the Bacteriological Code. British

bacteriologists are likely to remain faithful to thenames they now use and to modify them when there issufficient evidence that a change is needed. The listof species maintained- by the National Collectionof Type Cultures, shortly appearing as a M.R.C. Memo,will be a valuable guide to current British practice.

Chloromycetin in Rickettsial InfectionsTHE efficacy of the antibiotic, chloromycetin, in

scrub typhus is likely to prove a discovery of capitalimportance. The first results of the Anglo-Americanclinical trial proceeding in Malaya suggest that we atlast have a potent remedy for the rickettsial diseases.The antibiotic was isolated in 1947 by EHRLICH andcolleagues in Detroit from a soil actinomycete, andits active principle, obtained in crystalline form, wasfound to differ from any antibiotic so far describedin containing both nitrogen and non-ionic chlorine.In laboratory infections chloromycetin, weight for

weight, appeared more effective against R. prowazekiin chick embryos than any other agent tested underthese experimental conditions, and large doses pro-duced no symptoms in animals. These encouraginglaboratory results demanded clinical trial in humantyphus infection, and satisfactory results were claimedin a few cases of epidemic typhus in Mexico earlythis year. Since March, SMADEL and other research-workers from the U.S. Army and the University ofMaryland have been collaborating with LEWTHWAITEand SAvooR of Kuala Lumpur in a clinical trial inscrub typhus, and preliminary results were reported 2at the International Congress on Tropical Medicine 3at Washington, D.C., in May.

Scrub typhus, or tsutsugamushi fever, was one ofthe major medical problems of the Burma campaign.The disease is indigenous to a large part of tropicaland. subtropical Asia, but its extent was not realiseduntil large numbers of troops were put into junglepreviously unvisited by white men. It has long beenrecognised in Malaya, and much work has been doneon it there by LEWTHWAITE and his colleagues at theInstitute for Medical Research, Kuala Lumpur; so itis fitting that this institute was chosen as the head-quarters of the trial. The vector of the disease is a

1. Ehrlich, J., Bartz, Q. R., Smith, R. M., Joslyn, D. A., Burkholder,P. R. Science, 1947, 106, 417. See annotation, Lancet, 1947,ii, 952.

2. Smadel, J. E., Woodward, T. E., Ley, H. L. jun., Philip, C. B.,Traub, R., Lewthwaite, R., Savoor, S. R. Released by theDepartment of the Army, Technical Information Office,Washington, D.C.

3. See Lancet, May 29, p. 842.