REVIEW — TROPICAL MEDICINE, ETC. 155 



Hutcheon' has a good paper on biliary fever in dogs, and quotes Lounsbury as follows : — Canine Piro- 

 Like all other IxodiniB, both the cattle tick and the dog tick pass through three active life stages, viz., the plasmosis — 

 larval, nymphal aud adult. Preparatory to the transformation from one stage to the next, the feeding of the conlimicd 



tick is suspended ; thus, after an interval of variable duration, the old skin is ruptured, the tick crawls from it, 

 aud very soon seeks to renew its attack. The cattle tick normally stays on one animal throughout the several 

 changes. It remains attached to the .skin by its rostrum. After it suspends feeding, both as a larva and as a 

 nymph, and hence, on the completion of the moult which follows, it has only to re-attach itself to the animal 

 by its new mouth part, an act which it performs almost at once. The dog tick, on the other hand, perhaps 

 because it infests an animal more energetic than an ox in locating and destroying skin parasites, has the habit of 

 invariably loosening its hold and seeking shelter in the ground as soon as it ceases feeding before a moult, and, in 

 consequence, it has the trouble of finding a host three times in its life instead of once, as with the cattle tick, and 

 more often than otherwise a different dog is found each time. 



But a more troublesome peculiarity than the change of a host at each moulting, was the fact, experimentally 

 proved, that although the infective parasite is passed from the infected mother tick through the egg to the larval 

 tick hatched from it, yet, although this young tick evidently harbours the infective parasite, through its larval and 

 nymphal stages, it eacmot communicate the parasite to a susceptible host until it arrives at its m.ature or adult stage. 



He mentions that Robertson failed to confirm the results obtained by Nocard and IMotas 

 as regards prolonged immunity {see page 154), but agrees with their observations on 

 phagocytosis. Speaking of preventive and curative remedies, he says : — 



There can be little doubt that if a safe and effective method of preventive inoculation could be discovered, 

 one that could be applied say every six months in order to maintain the immunity, that would be the most 

 satisfactory method, and I am not without hope that such a means may be discovered. 



He recommends calomel and quinine as early as possible in the disease. 



Wetzl-* records a case of recovery under careful feeding with eggs, sugar, milk and 

 treatment with ferrura peptonatum cum arsenic. Gonder'* treated ten dogs with atoxyl in 

 varying doses, but was unable to observe any effect either on the incubation period or the 

 course of the disease. 



Plague. The more the Sudan is brought into contact with the outside world the 

 greater the risk of invasion by plague. Plague is endemic in Uganda and on the eastern 

 shore of the Eed Sea, while of late years Egypt has been constantly re-infected. Hence the 

 whole question of plague is one of very considerable importance, more especially since the 

 establishment of traffic on the Port-Sudan- Atbara railway. 



Naturally papers on preventive methods are those likely to be most useful, but certain 

 others will be considered as well. Klein, ^ in his recent book, when discussing the analysis 

 of plague materials, alludes to the great importance of using at once plate cultures in 

 preference to tube cultures of solid or fluid media, and, later, has some useful notes on 

 microbes simulating B. pestis. Amongst these are B. proteus vulgaris, B. coli, B. hristolense, 

 an organism found in dead rats on ship-board and showing marked bi-polar staining, 

 B. myxoides and B. mtiris. He indicates how mistakes may be avoided, and lays stress on the 

 necessity for examining any organism obtained from a suspicious case in hanging drop 

 preparation. This in itself will exclude many bacteria, for P. pestis is, of course, non-motile. 



IMacConkey'^ has a paper on the B. psendo-tuberrnlosis rodentium (Pfeifl'er) which, both 

 morphologically and culturally, resembles B. pestis more than any other known organism. 

 He found that, by inoculations of this bacillus, it was possible to immunise guinea pigs and 

 rats against B. pestis, the immunity sometimes lasting for a period of six months. 



In dealing with protective inoculation, Klein describes the preparation of his own new 

 plague prophylactic, made from the organs of animals dead of plague, and compares it 

 with Haffkine's fluid, saying : — 



When it is borne in mind (1) that this dried prophylactip does not require more than about ten to twelve days 

 for its preparation — Haffkine's requires four to six weeks ; (2) that a large amount can be prepared of uniform 

 strength; (3) that its efficacy is easily standardised by injection into the rat; (4) that, being dry .ind sterile, it 

 can be preserved without any antiseptic and unaltered for any length of time ; and (5) that the protection 

 afforded by its injection into the rat is of considerable duration, certainly many weeks ; and last, but not least, 

 that the cost of preparation is incomparably smaller ; the superiority of this organ-prophylactic to Haffkine's 

 prophylactic must be obvious. 



' Hutcheon, D. (November, 1907), "Biliary Fever in Dogs. Malignant Jaundice or Canine Piroplasmosis." 

 Journal of Tropical I'eterinanj Science, Vol. II., No. 4. 



- Wetzl, T. (February, 1908), "On Piroplasmosis in Dogs." Quoted in Journal of Tropical Vctcrinarij Science, 

 Vol. Ill, No. 1. 



= Gonder, R. (1907). Arh. n. d. K. Gcsundhcitsamte, Bd. XXVII, fasc. 2. 



•* Klein, E. (London, 1906), "The Bacteriology and Etiology of Oriental Plague." 



" MacConkey, A. T. (.June, 1908), "On the Relationship between Bacillus Pseudo-tuberculosis Rodentium 

 (Pfeiffer) and BaciUus Pestis." Journal of Hygiene. 



* Article not consulted in the original. 



