Nov. 15, 1883] 



NA TURE 



61 



success such as has attended the artificial cultivation of 

 the Salmonida:) states, without apparent proof, that the 

 cultivation might go on after the removal of the eggs 

 from the parent. Should this be so, choice must then 

 lie between the methods of Messrs. Cornish and Kent. 

 The latter has overlooked the fact that our Irish lobster 

 fisheries appear to be capable of much greater develop- 

 ment, and we doubt how far an accusation brought against 

 the " West-end chefs'' is a logical one. We are at a loss 

 to see the drift of Mr. K. Cornish's remarks, which form 

 part of the discussion upon these two papers. 



Early in the career of these meetings, our freshwater 

 fisheries received attention at the hands of Sir Jas. 

 Maitland, whose liberality in the matter of salmon-culture 

 is w^ell known in all fishing circles. The author, who re- 

 gards the artificial propagation of the Salmonidje as in 

 its infancy, records the technique and results of a long 

 practical experience, and indicates lines for future investi- 

 gation, both as regards the migratory and non-migratory 

 forms. He shows that by skilful attention he can rely 

 upon hatching out 99 per cent, of Loch Levan trout ova, 

 and, while discussing all sides of the question, he wisely 

 points out that the object to be aimed at is "not to 

 incubate the largest number of eggs in a given space," 

 but so to manipulate them that "the largest number of 

 healthy fish may result" — a statement involving diffi- 

 culties for the study of which we must refer the reader to 

 the paper itself. Intimately connected with this depart- 

 ment is the question of the salmon-disease fungus, which 

 forms the topic of a paper on " Fish Diseases," by Prof. 

 Hu.xley. The author's investigations in the matter are 

 well known to readers of Nature, but all connected 

 with Ireshwater fishing owe a debt of gratitude to the 

 learned Professorfor having thus sifted a voluminous litera- 

 ture upon the subject, and diagnosed in faultless style 

 this pest. Its geographical limits are — for the first time — 

 mapped out ; the fuugus is shown to cause, and not 

 merely accompany, the disease, and its propagation is 

 conclusively shown to be favoured by causes which 

 though unknown must necessarily be limited. Every 

 inducement is given to the daily worker among these 

 fiihes to cooperate in the further study of the disease, in 

 even the purely scientific aspects of which much yet 

 remains to be done. The remarkable fact that the disease 

 is in no way correlated with the "productiveness" of 

 a river is fully demonstrated, and must carry its own 

 lesson. 



A somewhat analogous topic forms subject-matter for a 

 paper on " The Destruction of Fish by Internal Parasites," 

 by Dr. S. Cobbold. There is, however, the most marked 

 contrast between it and that of Prof. Huxley, and we 

 venture to say that the statements made on the first two 

 pages and elsewhere, are calculated to frighten rather than 

 encourage (by appealing to the experimental side) possible 

 workers in a field for which the author claims so much. 

 We are compelled to put this work down with a feeling of 

 disappointment, the more so seeing that much of the 

 space which might have been turned to better account 

 is devoted either to a mere reiteration of statements 

 made again and again by the author during the earlier 

 sittings of the Conference, or to needlessly lengthy and 

 verbose discussions upon minor points, to the exclu- 

 sion of more important ones. 



The all important topic of "Food of Fishes'' is 

 attacked by Dr. Day. There is much in his paper that 

 is of value, he having incorporated the observations of 

 others with his own to the best advantage. The extreme 

 importance of this subject is obvious to all concerned, but 

 when — to say nothing of the question of inter-preying — 

 we consider the extent to which it is known that the 

 food of fishes may vary under conditions of most of which 

 we know absolutely nothing, it is obvious that there opens 

 up a field of labour, involving all sorts of side issues, work 

 in which must necessarily be both prolonged and tedious. 



The paper, however, suggests certain lines along which a 

 fruitful advance might be made. In the discussion which 

 followed, the chairman (Prof. Huxley), taking a philo- 

 sophic grasp of the question, resolves it into a balance in 

 favour of " the ultimate store of food " furnished by " the 

 Diatomaceae which occur on the surface." 



Mr. R. B. Marston, in an e.xceedingly practical paper 

 on " Coarse Fish Culture," adduces reasons for which it 

 is obvious that repopulation of our fresh waters must goon 

 as matters stand, and can be very beneficially maintained. 

 The question is one of growing importance, especially 

 as it affects those who, although living far inland, still 

 have the power of rearing good fish-food. We doubt, 

 however, how far it is not possible to obviate certain of 

 the difficulties mentioned, by more careful " nursing" 

 alone. In advocating the introduction of the prolific 

 Black Bass, the writer makes a statement, partly borne 

 out by the experience of the Marquis of Exeter who first 

 introduced the fish into Britain, but diametrically opposed 

 by that of Sir Jas. Maitland— and which, if correct, is of 

 great importance— viz. that it "thrives best in just those 

 waters which are not suited to trout and salmon." 



It is well known that the natural salmon stock of five 

 of our largest rivers is practically exterminated, and that 

 the fish present themselves annually at their unsavoury 

 mouths, but to be baffled by causes, chief among which 

 is that of pollution ; in other cases, less markedly offen- 

 sive, the fish are know-n to be slowly but certainly receding 

 The Hon. W. F. B. Massey Mainwaring, in a paper upon 

 " The Preservation of Fish Life in Rivers by the Exclu- 

 sion of Town Sewage," first points out the main causes of 

 actual death, and then proceeds to advocate the claims of 

 the well-known A. B.C. process, exhibited by the Native 

 Guano Company. For this he claims success, greater 

 than that which has attended any such known chemical 

 method, all at present pointing to irrigation and inter- 

 mittent-downward filtration, as the best solution of the 

 difficulty. All the artificial breeding in the world cannot 

 be of avail in waters thus becoming more deadly, and to 

 the chemist the utilisation of waste offers a good field for 

 work. There are other doubtful points about this paper, 

 beyond the limits of a short notice, but it is sincerely to 

 be hoped that when the present inquiry into the London 

 sewage question terminates, the adoption of some treat- 

 ment beneficial to our waters may perpetuate its action. 



Closely allied are the interests of " Forest Protection," 

 advocated by Mr. D. Howitz, the more especially as there 

 is evidence to show that the disappearance of salmon has 

 been at limes associated with the clearing of forests. The 

 author points out that, while the question has naturally 

 more interest for other countries than our own, it is pos- 

 sible to maintain throughout the year, by the interaction 

 of natural forces, a better equilibrium of life in shallow 

 water. Although much yet remains to be done in this 

 work, the arguments adduced are practical and weighty. 

 The author advises the use of certain trees as being, from 

 his own experience, preferable, the question of growth of 

 timber not being overlooked. 



All tlie aforementioned papers point indirectly to the 

 " outcome " of the present movement, in so far as they 

 suggest methods of improvement. Those which remain 

 are either directly addressed to that subject itself, or to 

 others demanding immediate attention. 



Prof. Leone Levi brings forward a mass of statistical 

 knowledge upon "The Economic Condition of Fisher- 

 men," stated to be " generally unsatisfactoi7." The paper 

 abounds in useful information, not the least important 

 being that which deals with the relationships existing 

 between boat-owners and fishermen ; the author also 

 states that at present the workers are in proportion exces- 

 sive " to the amount of production," and wisely recom- 

 mends a "weeding" of those parasites— neither fishermen 

 nor fools— said to exist. The "fortunes of the fisheries 

 and agriculture in the last twenty years " are significantly 



