400 



NA TURE 



[February 23, 1899 



number to sixty-seven species, excluding certain Barbels de- 

 scribed by Riippell from Lake Tzana and some other species 

 of doubtful origin. This number, however, was considerably 

 in excess of the reality, as many of Heckel's species were after- 

 wards found to be synonyms. .Sixty probably represented the 

 number of the known species at that time (1847). I'etherick, 

 while in Egypt in 1861-63, made, at Dr. (liinlher's request, a 

 collection of fishes for the British Museum. The specimens 

 were obtained at Cairo, Khartum, and dondokoro, and were 

 described by Dr. Gimther in an appendix to I'ethcrick's 

 "Travels," published in 1869. The collection contained 

 eighteen new additions to the fauna, and raised the number of 

 known species to eighty-two. It thus materially advanced our 

 knowledge of the piscine fauna of the Nile ; and as Dr. Giinther 

 not only figured eight species, but at the same time added a 

 description of every form, his contribution has proved most 

 useful. 



Since 1869 the fishes of the Nile have been almost completely 

 neglected. .Sauvage, however, in 1880, .idded a new species 

 from Lake Maryul ; I'fefier, in 1888, mentioned the species 

 obtained by Stuhlmann in Lgypt ; and Mitchell, in 1895, brought 

 to light and figured a new Chromis from Lake Menzaleh, and 

 gave an account of the edible fishes of that lake. In 1896, 

 Prof. Vailiant, in revising the Synodont.s, pointed out the 

 existence in llic White Nile and at Khartum of two hitherto 

 unrecognised forms. 



At present, therefore, about ninety species of fishes are known 

 to inhabit the river, but this number, considering the vast extent 

 of its waterway and the very diverse physical conditions which 

 characterise many parts of its course, cannot be considered as at 

 all approaching finality. 



The collections hitherto made from the Nile have principally 

 been obtained from below the First Cataract ; indeed Riippel 

 and I'etherick are the only two collectors who had opportunities 

 to investigate the river above Assuan. The former distinguished 

 traveller and naturalist largely collected in Lower Egypt, and 

 not a few of I'etherick's specimens were from the same region. 

 In Dr. Giinther's account of this collection only six species 

 were distinctly recorded as coming from Gondokoro, Khartum, 

 and the White Nile, while thirteen, besides the foregoing six, 

 species were stated to belong properly to the reach of the 

 Nile above the Sixth Cataract. 



In dealing with the distribution of fishes in the Nile, the 

 use of the phra.se Upper Nile, unless what is meant by the 

 term is clearly defined, leads to endless confusion. Dr. (nmther 

 has made it quite evident in what sense he used the terms Lower 

 and Upper Nile ; but it is to be feared that the latter term has 

 generally been used in a wider .sense, and has included the river 

 from Phike southwards to the Lakes. While we possess a 

 fragmentary knowledge of the species from Khartum southwards, 

 the immense tract of the Nile from the I'irst to the .Sixth 

 Cataract remains practically untouched. 



The great mass of the forms known from below the First 

 Cataract is largely made up of edible species, and a careful 

 consideration of the literature bearing on this part of the Nile 

 favours the supposition that the collections of fishes which have 

 been formed in the past have been chiefly obtained by the 

 assistance of the fishermen along the banks of the river and from 

 the fish-markets of the country. However, in a great river like 

 the Nile, uni<|ue in its annual inundations and in other charac- 

 ters, a much more thorough course of procedure than the fore- 

 going is absolutely necessary in order to obtain an accurate 

 conception of the true nature of its fauna. 



Apart from the mere knowledge of how many species of fishes 

 exist in the river, great economic questions come to the front 

 when their life-history is studied. These, however, can never 

 be usefully worked out until there exists on record a basis 

 on which to work, in the form of a detailed description of each 

 species accompanied, as far as practicable, by a figure. 



The inundations of the Nile exercise a powerful influence on 

 the distribution of the fishes contaiiicil in its waters, while, on 

 the other hand, the cataracts retard their range. A multitude 

 of questions of great interest bearing on the life-history of the 

 species thus at once .suggest themselves in view of the physical 

 features encountered in this marvellous river. 



Moreover, as within the next few years a change will be 

 effected in the distribution of the Nile waters by the construction 

 of the controlling-powers now in course of erection at Phike 

 and Assiut, and as other similar structures or dams are likely to 

 follow toward the south, all of which are ceitain ultimately 



NO. 1530, VOL. 59] 



to limit more or less the range of certain species of fishes, it i 

 much to be desired that, before any of these triumphs of the 

 Department of Irrigation have been completed, we should be 

 placed in possession of the main features and present condition 

 of the piscine fauna of the great reaches of the river. 



The present time seems also extremely opportune for the^ 

 commencement of such an investigation, as the authorities of 

 the Congo Free State have satisfactorily inaugurated a .Survey 

 of the Congo, and have already published some of the results. 

 Were a corresponding .Survey for the Nile entered upon by the 

 Egyptian Government, and were the description of the species 

 entrusted to Mr. G. \. Boulenger, F.K.S., who is describing 

 the fishes of the Congo for the Congo Free .State, and who is 

 prepared to place his services at the disposal of the Egyptian 

 Government free of all charge, the two surveys would mutually 

 benefit each other, as the materials afforded by the one would 

 throw light upon those of the other, many of the species of the 

 two great rivers being closely allied. The results would doubt- 

 less be unique, and would form a lasting contribution to human 

 knowledge, and, moreover, would be of great practical utility 

 to both States. 



The foregoing are a few of the grounds on which the proposed 

 Survey is .advocated. 



Scope of the Siinxy. 



It is recommended that some one who has had a zoological 

 training should be appointed to superintend and carry out all 

 the arrangements that it would be necessary to make for the 

 formation of a representative collection of the fishes of the Nile, 

 and who would lie able likewise to discharge efficiently the 

 other duties detailed in this memorandum. As it is very 

 important thtit the form and life-colours of the different species 

 should be accurately recorded by outline sketches, the Super- 

 intendent should be ()ualified to carry out such a work, because 

 the information which such drawings would afford, if made by 

 one who h,id a correct eye for colour, would be of great use to 

 Mr. Boulenger when he came to describe the individual species. 

 The highly-finished drawings for the illustration of the volume 

 of " The Fishes of the Nile" would be made in London under 

 Mr. Boulenger's per.sonal supervision. A colloquial knowledge 

 of Arabic would be of great advantage to the Sujwrintendent, as 

 it would enable him to obtain direct, from the fisher-folk on the 

 banks of the river, much useful information on the subject of his 

 investigations. Moreover, to properly discharge his various 

 duties, the .Superintendent should be a strong and healthy man. 



An investigation of the entire river from the sea to Lailo, and if 

 possible through the .(»(/i/and rapids between Lado and Dufik- 

 to its origin in the Albert Nyanza, should be kept in view as 

 the ultimate aim of the Survey, which might be followed, later 

 on, by similar researches into the fauna of the Nilotic lakes as 

 a whole. Such a work is now proceeding on Lake Tanganyika, 

 an intermittent elfluent of the Congo, inaugurated by ^Ir. J. E. 

 S. Moore, under the auspices of the Royal .Society. Possibly 

 wlien Mr. Moore has completed his work cm that kike he may 

 be able to direct his attention to Lake Kivu, and afterwards he 

 might be in a position to cross the watershed to the Nile lakes 

 and determine the character of their fauna as well, returning to 

 civilisation by the Nile. 



Although these are the lines on which a Survey of the Nile 

 .should be conducted to render it scientifically complete, it is 

 suggested that the Survey should for the present be of a mote 

 limited character. 



In the first instance, a series of stations should he selected 

 along the river extending at intervals from the Delta, to Lado in 

 the territory leased by the Egyptian Government to the Congo 

 Free State, and as far to the south of this as possible. And it 

 may be mentioned that were the Egyptian tjovernment to 

 inform the Secretary of State for the Congo Free Slate that an 

 investigation into the fi.shes of the Nile was to be undertaken 

 under its aus|>ices, there is every reason to believe that the 

 Secretary o( State would issue orders for a collection of fishes 

 to be formed by the Belgian officers at Lado and transmitted 

 down the Nile to Cairo. 



The following is a provisional list of the jilaccs recommended 

 at which collections .should be brought together, v'v/. Damictta, 

 Lake Menzaleh, Roselta, Lakes Burlus, Edku, and Maryul, 

 Mahallet el Kebir, below the Barrage, above the Barrage, Cairo, 

 Benisuef, Birket el Kurun (and two or three stations through- 

 out the Fayum), .Vssiut, Luxor, Edfu, Assuan, Phil.v, Korosko, 

 Wadi Haifa, .Vkasheh, Dongola, Ambuk..!, .\bu Uamcd, 



