36 



NA TURE 



[November 14, 1907 



eluded another new species of Ceratoisis and five other 

 forms previously described. Prof. Hickson and Mr. 

 F. H. Graveley deal with the hydroid zoophytes, which 

 include some interesting forms, especially Hydraclinia 

 dendritica, n.sp. Though there is no definitely new 

 generic type, there are ten certainly new species and 

 five more probably new — a very large proportion out 

 of a total of twenty-five. It may be noted that only 

 two of the twenty-five were got outside the limits of 

 MciMurdo Bay and the edge of the great ice-barrier, 

 so that we have here a fine representation of the 

 hvdroid fauna from the most southerly limit of our 

 knowledge of marine zoology. It is also interesting 

 to find that three of the species are common on British 

 coasts. Dr. John Rennie makes a note on the extra- 

 ordinarily long tentacles of some unknown siphono- 

 phore. They were about as stout as an ordinary boot- 

 lace and nearly twenty feet in length. Mr. Hodgson 

 gives a graphic account of the difficulties attending 

 their capture. 



.'^.mong the sponges, Mr. R. Kirkpatrick found four 

 species of Tetractinellids, forty-three Monaxonellids, 

 twenty-four Calcarea, no Keratosa, and ten species of 

 Hexactinellids. He describes the Hexactinellids, of 

 which three were new genera and eight new species. 



The third volume ends with a report on the marine 

 algcB (Pheophycea? and Florideas) by Mr. Gepp and 

 Mrs. Gepp, a description of a new coralline by Dr. M. 

 Fo.slie, and an account of the mosses by M. Jules 

 Cardot. It need hardly be said that with such bulky 

 volumes before us it has not been possible to give more 

 than a hint of the amount of sound and interesting 

 work which they contain. 



THE CURE AND PREVENTION OF SLEEPING 

 SICKNESS. 



THE sleeping sickness is, and unfortunately con- 

 tinues to be, the most burning problem of 

 European colonisation in equatorial Africa. Like any 

 other medical problem, that of sleeping sickness has 

 two sides, which may be distinguished broadly as 

 prevention and cure. Investigators in all parts of 

 the world have been experimenting actively with the 

 object of finding a drug, or method of treatment, 

 which shall act in sleeping sickness as quinine does 

 in malaria ; that is to say, which shall destroy the 

 parasites in the blood, without seriously affecting the 

 health of the patient. Up to the present, the atoxyl 

 treatment has given the best results, but it has often 

 failed to produce more than temporary amelioration, 

 and it is open to doubt if it has produced a complete 

 cure in any case, while, like other arsenical compounds, 

 it may have serious toxic effects. On Thursday last, 

 however, a coinmunicatlon was made to the Royal 

 Society by Drs. H. G. Plimmer and J. D. Thomson, 

 of the Lister Institute, on the effect of certain anti- 

 mony salts; and, to judge from the preliminary ex- 

 periments on rats, these compounds appear to be far 

 more efficient in their curative action, and at the same 

 time less toxic in their effects, than atoxyl. The e.\- 

 periments will be extended at once to larger animals 

 and to man, and though it would be premature to say- 

 that the long-sought-for cure has been found, the out- 

 look is certainly more full of hope than it has ever 

 been before. 



The question of the prevention of sleeping sickness 

 is. of course, bound up with the etiology of the 

 disease. It is known that the disease is caused by 

 the presence of a minute flagellate parasite or "try- 

 panosome," first in the blood, later in the cerebro- 

 spinal fluid of the patients; and it is known that the 

 trypanosomes are conveyed from diseased to healthy 

 subjects by the bite of one, possibly more than one, of 

 the species of blood-sucking tsetse-flies. It cannot be 



NO 1985 VOL. yy] 



too emphatically stated, however, that the tsetse-fly 

 is not, as so oft«n stated, the "cause " of the disease; 

 if the fly be not infected, its bite is harmless, and 

 Koch and others have reported the existence of large 

 areas in which the fly swarms, but in which sleeping 

 sickness does not as yet exist, although the necessary 

 condition for its diffusion is found. 



It follows that the problem of prevention may be 

 attacked in two ways ; extirpation of the fly, or con- 

 trol of the infection. Considering the vast extent 

 of the range of the species of tsetse-flies in Africa, 

 considering, further, that these flies, being viviparous, 

 have no free larval stages in which they can be de- 

 stroyed, like mosquitoes, any notion of extirpating 

 tsetse-flies must be considered as frankly Utopian. The 

 measures adopted bv our Governinent are wisely 

 directed towards controlling the spread of the infec- 

 tion. Since the flv haunts thick bush on the lake- 

 shore exclusively, the jungle is to be destroyed at all 

 ports, ferries, and landing-places on the lake, where 

 it is unavoidable that human beings should visit the 

 lake-shore ; at other points the natives are to be re- 

 moved from the shore, and persuaded or coerced to 

 live out of the effective range of the fly. Natives 

 known to be diseased are to be segregated, pre- 

 vented from wandering into the " fly-belts," and 

 placed under treatment. By this means it may be 

 reasonably expected that the spread of the infection 

 may be checked. 



There remains, however, the possibility that some 

 wild animal mav play a part in spreading the infec- 

 tion, since other animals besides man are known to 

 be susceptible to the trypanosome when inoculated 

 with it in the laboratory. As yet, however, no verte- 

 brate, otlier than the human species, has been proved 

 to harbour the trypanosome of sleeping sickness in 

 a state of nature. It is well known, however, that 

 other species of trvpanosomes, in no way connected 

 with sleeping sickness, are found cominonly in wild 

 animals of all classes; and it may be added that the 

 tsetse-flies are quite as willing to suck the blood of a 

 reptile or bird as that of a mammal. Hence there is 

 always the possibility that some species of wild animal 

 may act as a " reservoir " from which the supply of 

 the trypanosome of sleeping sickness may be kept 

 up indefinitely through the agency of tsetse-flies. It 

 is. therefore, of the utmost importance that further 

 researches on the etiology of sleeping sickness should 

 b'^ carried on, with the special object, among others, 

 of discovering any such indigenous source of the 

 disease, for it need hardly be pointed out that it would 

 be of little use to prevent tsetse-flies becoming infected 

 from human beings if they could also obtain the 

 infection from natural sources. 



THE POLLUTION OF RIVERS. 



ON Thursday, October 31, an influenti.il deputa- 

 tion froni the British Science (iuild inter- 

 viewed Mr. Burns, M.P., at the Local Government 

 Board, upon the subject of legislation with respect 

 to the prevention of the pollution of rivers, and the 

 protection of the public against the contamination of 

 shell-fish. 



In most directions the tendency to the pollution of 

 our water supplies increases with the demand for pure 

 water, and the area from which such water can be 

 obtained in the neighbourhood of our towns is 

 diminishing. The existing local authorities have con- 

 flicting interests when dealing with river pollution, 

 and considerations of guarding the purity of streams 

 are often subordinated to those of refuse disposal and 

 manufacturing requirements. What too often 

 happens is that a sanitary authority, situated toward 

 .the head of the stream or upon one of its tributaries, 



