496 



NATURE 



[September 19, 1895 



1SS2, after seeing the first ten or twelve zoolc^cal reports through 

 the press. 



Within the last few months have been issued the two con- 

 cluding volumes of this noble series, dealing with a summary of 

 the results, conceived and written in a masterly manner by the 

 ;nt editor of the re|x>rts, Dr. John Murray. \n event of 

 rstrate importance in zoology as the completion of this 

 ^. ...L work ought not to pass unnoticed at this zoological gather- 

 ing. I desire to express my appreciation and admiration of Dr. 

 Murray's work, and I do not doubt that the Section will permit 

 me to convey to Dr. Murray the congratulations of the zoologists 

 present, and their thanks for his splendid seruces to science. 

 Murray, in these "Summary" volumes, has given definiteness 

 of scojx; and purpose, and a tremendous impulse, to that branch 

 of science — mainly zoological — which is comins; to be called 



Oceanography. 



Oceanography is the meeting ground of most of the sciences. 

 It deals with botany and zoology, ' ' including animal physiology " ; 

 chemistry, physics, mechanics, meteorology, and geolog)- all con- 

 tribute, and the subject is of course intimately connected with 

 geography, and has an incalculable influence upon mankind, his 

 distribution, characteristics, commerce, and economics. Thus 

 oceanography, one of the latest developments of marine zoology, 

 extends into the domain of, and ought to find a place in, every 

 one of the Sections of the British .\s.sociation. 



.•Uong with the intense specialisation of certain lines of zoo- 

 Ifigy in the last quarter of the nineteenth centur)-, it is important 

 to - notice that there are also lines of investigation which 

 require an extended knowledge of, or at least make use of the 

 results obtained from, various distinct subjects. One of these is 

 oceanography, another is bionomics, which I have referred to 

 .;1> ^ c, a third is the philosophy of zoolog)-, or all those studies 

 liear uiwn the theory of evolution, and a fourth is the in- 

 itinn of practical fisher)' ])roblems — which is chiefly an 

 ■ •f marine zoology. Of these four subjects — which 

 \ ic enough in the detailed investigation of any (xir- 



li..,..., ,.,-:.lem, are .synthetic in drawing together and making 

 use of the various divergent branches of zoology and the neigh- 

 liouring sciences — oceanography, bionomics, and the fisheries' in- 

 vestigation, are most closely related, and I desire to devote the 

 remainder of this address to the consideration of some points in 

 connection with their present position. 



Dr. Murray, in a few only too brief paragraphs at the end of 

 hi- 'ktailcd summary of the results of the Challenger Expedition, 

 \i' h I have alluded lo above, stales some of the views, highly 

 J j.jstive and original, at which he has himself arrived from his 

 ;l- ex|>erience. Some of his conclusions are very valuable 

 . i nliutions to knowledge, which will no doubt be adopted by 

 ni.irine zoologists. Others, I venture to think, are less sound 

 and well Tiunded, and will scarcely stand the test of time and 

 furlher experience. But f<ir all such statements, or even sug- 

 j;c-iiin-,, we should be thankful. They do much to stimulate 

 f, ,• .r i.s.arch, they serve, if they can neither be refuted nor 

 as working hypotheses ; and even if they have to lie 

 I dpandoned, we should bear in mind what Darwin has 



said iij> to the diflTcrence in their influence on science between 

 erroneous facts and erroneous theories. " False facts are highly 

 i ■ ' I -s of science, for they often endure long ; 



I orted by some evidence, do little harm, 



I , ....... ..ilutary pleasure in proving their falseness ; 



and when this is done, one path towards error is closed, and the 

 road 10 truth is often at the same time opened " (Darwin, " The 

 Descent of Man," second cilit. 1882, p. 606). 



Wiih all respect for Murray's work, and fully conscious'of my 



lity in venturing to difl'er from one who has had such 



1 cxi)erience of the sea ami its problems, I am con- 



■ ''v di.s.agrecmcnt with some of his conclusions. 



10 do .so by the belief that Murray will 

 1 . >t compliment which zoologists can pay 



to luM work is lo give it careful, detailed consideration, and dis- 

 c««» it '■riii'-nlly. lie will, I am sure, join me in the hope that, 



V ' mine prove the false ones, we maybe able, 



t to close a "path towards error," and 



; ' • I ruth." 



I which Murray lays considerable 



•11 of which he devotes a prominent 



• Cicncral Observations on the Distribution of 



lis," is the presence of what he has called a 



' uij'J IiiiL .iruund coasts at a depth of about one hundred 



NO. 1 35 1, vol.. 52] 



fathoms. It is the point "at which minute particles of organic 

 and detrital matters in the form of mud begin to settle on the 

 bottom of the ocean." He regards it as the great feeding 

 ground, and a place where the fauna is most abundant, and from 

 which there have hived ofl', so to speak, the successive swarms or 

 migrations which have peopled other regions — the deep waters, 

 the open sea, the shallow waters and the estuaries, fresh waters, 

 and land. Murray thus gives lo his mud-line both a present and 

 an historic importance which can scarcely be surpassed in the 

 economy of life on this globe. I take it that the historic and the 

 present imi)ortance stand or fall together — that the evidence as 

 to the origin of faunas in the jiast is derived from their distribu- 

 tion at the present day, and I am inclined to think that Murray's 

 opinion as to the distribution of anim.ils in regard to the mud- 

 line is not entirely in accord with the experience of specialists, 

 and is not based upon reliable statistics. Murray's own state- 

 ment is(" C//<j//(-H.fir>- Expedition, Summary," vol. ii. p. 1433) • — 

 "A depth is reached along the continental shores facing the 

 great oceans immediately below which the conditions become 

 nearly uniform in all parts of the world, and where the fauna 

 likewise presents a great uniformity. This depth is usually not 

 far above nor far below the loofathom line, and is marked out 

 by what I have elsewhere designated as the Mud-line. . . . 

 liere is situated the great feeding ground in the ocean . . ." 

 and he then goes on (p. 1434) to enumerate the Crustaceans, 

 such as species of Calaniis, Eiiclurla, Pasipluca, Crangon, Calo- 

 carts, Panrialiis, Hippolyte, many amphipods, isopods, and im- 

 mense numbers of schizojxids, which swarm, with fishes and 

 cephalopods, immediately over this mud deposit. Now I venture 

 to think that the experience of some of those who have studied 

 the marine zoology of our own coasts does not bear out this 

 statement. In the first place, our experience in the Irish Sea is 

 that mud may be found at almost any depth, but is ver)- varied in 

 its nature and in its source. There may even be mud laid dow n 

 between tide marks in an estuary where a very considerable cur- 

 rent runs. .\ deposit of mud may be due to the jiresence of an 

 eddy or a sheltered corner in which the finer particles susjiended 

 in the water are able to sink, or it may be due to the wearing 

 away of a limestone beach, or to quantities of alluvium brought 

 down by a stream from the land, or lo the presence of a sub- 

 merged bed of boulder clay, or even, in some places, lo the 

 sewage and refuse from coast towns. Finally, there is the deep- 

 water mud, a very slifl" blue-grey substance which sets, when 

 dried, into a firm clay, and this is, I take it, the mud of which 

 Dr. .Murray writes. But in none of these cases, and certainly 

 not in the last mentioned, is there in my exi)crience or in that of 

 several other naturalists I have consulted, any rich fauna .associ- 

 ated wilh the mud. In fact, I would regard mud as suppiuting 

 a comparatively poor fauna as compared with other shallow 

 water deposits. 



For practical purposes, round our own British coasts, it is still 

 convenient to make use of the zones of depth marked out by 

 Forbes. The first of these is the " Littoral zone," the space lie- 

 twcen tide marks, characterised by the abundance of sea-weeds, 

 belonging to the genera I.uhina, Fiiiiis, Enteroinorpha, Poly- 

 siplionia, and others, and by large numbers of individuals belong- 

 ing lo common species of Palanns, A/v/iliis, Litlorina, Pnipiira, 

 and Patella amongst animals. "The second zone is the 

 " I.aminarian,'' which extends from low-water mark to a deplh 

 of a few fathimis, characterised by the .abundant growth of large 

 sea-weeds belonging to the genera I.aiiiinaria, Alaria. aiul 

 Ilimanllialia, and by the presence of the beautiful red seaweeds 

 (Floride;v). There is abundance of vegetable food, and animals 

 of all groups swarm in this zone, the numbers both of species and 

 of individuals being very great. The genera HeUion, 'J'rochu$, 

 and Laiuna arc characteristic molluscan forms in our seas. 

 Nest comes I'orbes' "Coralline" zone, badly so nameil, ex- 

 tending from ahoul ten to forty or fifly fathoms or so. Mere we 

 arc beyond the range of the ordinary sea-weeds, but the cal- 

 careous, coral-like Nullipores are present in places in such 

 abundance as to make up deposits covering the Moor of the .sea 

 for miles. Ilydroid zoophytes and poly/oa arc also aliundnnt, 

 and it is in this zone that we find the shell-beds lying ofl' our 

 coasts, produced by great accumulations of species of Pnhn, 

 Os/rea, Peaiiiniiliis, Piisns, and liiiuinnin, and forming rich 

 feeding grounds for many of our larger fishes. All groups of 

 marine animals are well represented in this zone, and .Inledon, 

 Ophiolhrix, Opli ioglypha, Ehalia, /nadiiis, and /iiirymniic. may 

 be mentioned as characteristic genera. Lastly, there is what may 

 be a|)proprialely called the zone of deep mud (although Forbes 



