NA rURE 



[November 7, 1907 



THE FISHES OF THE NILE.^ 

 ^pHESE two handsome volumes are a tribute to the 

 J- late Dr, John Anderson's zeal in the cause of 

 Egyptian zoolotjy, and a justification of the cordial 

 support which he had from Lord Lister, Dr. Gunther, 

 Sir E. Ray Lankester, and Dr. Sclater in prevailing 

 on the Esyptian Government to undertake the inquiry. 

 The author, the collector and the artist are to be con- 

 gratulated on this important contribution to African 

 ichthyology. Moreover, the region embraced in the 

 description, as shown in the two e.\cellent maps of 

 the Nile system — Upper and Lower— is one of great 

 interest to the general zoologist, for it contains the 

 sole survivors of an order (Polypterida) abundantly 

 represented from the Devonian to the Cretaceous, and 

 includes one of the remarkable Dipnoans. It is an 

 ;irea in which the rare electrical fishes Mormyrus and 

 Malapterurus (or, as the author has it, Malopterurus) 

 are mingled with the subtropical and tropical Gym- 

 narchus,"the curious Heterotis, the Characinidse, the 

 Siluridffi, Ophiocephalus, the Anabantidffi, and the 

 Cichlidas ; whilst by way of contrast these are associated 

 with the cosmopolitan Clupea finta and Miigil capita, 

 with the common Anguilla vulgaris and the ubiquitous 

 Morone labrax. Yet these do not exhaust the sources 

 of special interest, for not only were fishes, such as 

 the Nile perch, preserved as mum- 

 mies, their forms inscribed on 

 ancient monuments or perpetuated 

 in bronze models, but in this old- 

 world country the number of 

 fishes which carry and hatch their 

 comparatively large ova and pro- 

 tect their voung in the bucco- 

 pharyngeal cavity is remarkable. 



The problems connected with 

 the origin and distribution of the 

 fish-fauna are also replete with in- 

 terest, and though many of these 

 were dealt with by Mr. Boulenger 

 in his valuable address to the zoo- 

 logical section of the British .Asso- 

 ciation in South Africa, much yet 

 remains for future workers^ both 

 in substantiation and extension. 



In the brief introduction the 

 progress of the ichthyology of 

 the Nile is described from 1757, the date of 

 Hasselquist's " Iter Palaestinum," when only thir- 

 teen species from the Delta were known. With- 

 out going into detail, they had mounted up to eighty- 

 nine in " Dr. Giinther's account of the fishes of 

 Petherick's expedition, but did not exceed a hundred 

 when the Egyptian Government undertook the pre- 

 sent survey. " Now the total is 192, and no one has 

 had a greater share in this increase than the author. 



An important part of the introduction is the illus- 

 trated account given by Mr. Loat, the collector, of 

 the methods of fishing in the Nile, the accumulated 

 skill of many ages having given the native all the 

 practical advantages of his art, so that in this respect 

 he is not inferior to the English, American and 

 Japanese. The throwing- or casting-nets, circle-nets, 

 sweep-nets, modified trammel-nets, long nets like those 

 for sand-eels with a median pocket, push-nets, conical 

 wicker traps, elaborate weirs of stones which closely 

 resemble those at present in use in Japan, besides 

 baited and unbaited hooks, show how varied these 

 methods are. It is not to be supposed, however, that 



1 " Zoolooy of Egypt. The Pishes of the Nile." By G. A. Boulenger, 

 F.R.S. Vol. i., text. pp. 114-578; vol. ii., plates, pp. xviii+g/ plates. 

 (London : Published for the Egyptian Government by Hugh Rees, Ltd., 

 1907.) Two vols., price 8/. Bs. net. 



NO. 1984, vol,. 77] 



the casting-net is a novelty, for on the coast of Suf- 

 folk, for instance, an adept will throw it in a perfect 

 circle. Mr. Loat collected no less than 1 1,000 speci- 

 mens, and amongst these were thirty new species. 

 Moreover, just as the Irish use the fatal spurge-root in 

 their rivers, so the Egyptian pulverises the seeds of 

 Bcrbcra (or Mellettia) ferruginea, or "Burbcrra," for 

 poisoning fishes. In two or three hours thousands, it 

 mav be, rise to the surface. 



The thorough method in which Mr. Boulenger 

 treats his subject is apparent throughout ; elaborate 

 tables of twelve measurements, in addition to nine 

 notes of the number of spines, rays and scales in 

 diiferent parts, accompany each species. He, however, 

 evidently makes too much, at the expense of Riippell 

 and others, of De Johannis as a pioneer in Egyptian 

 ichthyology, for this author's descriptions and figures 

 have much that is incorrect in them. Moreover, there 

 is a tendency to split species where others group 

 them, and to group them where others split them, 

 the latter being just the fault he himself lately 

 criticised, and with justice, in Smitt. Further, in- 

 significant specific variations between the Nilotic fish- 

 fauna and that of West Africa need not be insisted 

 on too strongly where, as pointed out long ago, the 

 similarity is so great. In looking at the slight diversi- 

 ties between such species as Marcusenins discorhyn- 



ng at th. 



chiis, M. pcilierici, M. hudgetti, and M. taiiga)iicaniis, 

 the thought involuntarily asserts itself that in the future 

 a different view may be taken of their relationships. 

 Again, there are cases in which the indefatigable 

 author has examined 100 to 200 examples of a fish 

 normally possessing ten to eleven dorsal rays, but he 

 finds that three or four per cent, have seven or eight 

 rays only. It is surely unsatisfactory to describe such 

 a fish as possessing D. 7-10. A more correct method 

 would have been to record it as Dr. Gunther has 

 done, viz. D. (7-8) g-io. 



One of the most interesting features in the Cross- 

 opterygians is the frequent allusion to the labours of 

 the lamented Mr. J. S. Budgett, who contracted a 

 fatal illness whilst pursuing his valuable work on the 

 development of the group in the Niger Delta. Con- 

 siderable advances have been made in the Dipnoans, 

 that of the Nile (Protopterus aethiopicus) differing in 

 habit from P. anncctens of the West Coast. Of 

 Teleosteans there are nineteen families, and the author 

 gives two classifications, (i) an anatomical, and (2) one 

 based on external characters. Both are valuable. The 

 first family of (he Malacopterygians is the generalised 

 Mormyridae, remarkable for the large size of the 

 brain and the " problematic organ " above it, as well 

 as for their electric organ. Four families, each repre- 



