704 REPORT— 1895 



importaBce as the great feeding ground and place of origin of life in the ocean, 

 but he also (p. 1432) draws conclusions as to the relative numbers of animals taken 

 by a single haul of the trawl in deep and shallow waters ■which can scarcely be 

 received, 1 think, by marine zoologists without a protest. His statement runs 

 (p. 143l*) : ' It is interesting to compare single hauls made in the deep sea and in 

 shallow water with respect to the number of difierent species obtained. For in- 

 stance, at station 146 in the Southern Ocean, at a depth of 1,375 fathoms the 200 

 specimens captured belonged to 59 genera and 78 species.' That was with a 10-foot 

 trawl dragged for at most two miles during at most two hours. Murray then goes 

 on to say : ' In depths less than 50 fathoms, on the other hand, I cannot find in 

 all my experiments any record of such a variety of organisms in any single haul 

 even when using much larger trawls and dragging over much greater distances.' 

 He quotes the statistics of the Scottish Fishery Board's trawliugs in the North 

 Sea, with a 25 ft. trawl, to show that the average catch is 7'3 species of inverte- 

 brata and 83 species of fish, tlie greatest number of both together recorded in one 

 baul being 29 species. Murray's own trawlings in the West of Scotland gave a 

 much greater number of species, sometimes as many as 50, ' still not such a great 

 variety of animals as was procured in many instances by the " Challenger's" small 

 trawl in great depths.' 



Now, in the first place, it is cin-ious that Murray's own table on p. 1437, in 

 which he shows that the ' terrigenous' deposits lying along the shore-lines yield 

 many more animals, both specimens and species, per haul, than do the ' pelagic ' 

 deposits' at greater depths, such as red clays and globigerina oozes, seems directly 

 opposed to the conclusion quoted above. In the second place, I am afraid that Dr. 

 Murray has misunderstood the statistics of tiie Scottish Fishery Board when he 

 quotes them as showing that only 73 or so species of invertebrates are brought 

 up, on the average, in the trawl net. I happen to know from Mr. Thomas Scott, 

 F.L.S., the naturalist who has compiled the statistics in question, and also from 

 my own observations when on board the ' Garland ' on one of her ordinary trawling 

 expeditions, that the invertebrata noted down on the station sheet are merely a 

 few of the more conspicuous or in other ways noteworthy animals. No attempt is 

 made— nor could possibly be made in the time — by the one naturalist who has to 

 attend to tow-nets, water bottle, the kinds, condition, food, &c., of the fish caught 

 and other matters — to give anything like a complete or even approximate list of 

 the species, still less the number of individual.", brought up in the trawl. I submit, 

 therefore, that it is entirely misleading to compare those Scottish Fishery Board 

 statistics, which were not meant for such a purpose but only to give a rough idea 

 of the fauna associated with the fish upon certain grounds, with the carefully 

 elaborated results, worked out at leisure by many specialists in their laboratories, 

 of a haul of the ' Challenger's ' trawl. Of Dr. Murray's own trawlings in the West 

 of Scotland I cannot, of course, speak so positively, but I shall be surprised to 

 learn that the results of each haul were as carefully preserved and as fully worked 

 out by specialists as were the ' ('hallenger ' collections. 



Lastly, on the next L.M.B.C.- dredging expedition in the Irish Sea after the 

 appearance of Dr. Murray's volumes, I set. myself to determine the species taken 

 in a haul of the trawl for comparison with the ' Challenger ' numbers. The haul was 

 taken on June 23, at 7 miles west from Peel, on the north bank, bottom sand and 

 shells, depth 21 fathoms, with a trawl of only 4 ft. beam, less than half the size 



' One of the earliest of the ' Challenger ' oceanographic results, the classification 

 of the submarine deposits into 'terrigenous' and 'pelagic,' seems inadequate to 

 represent fully the facts in regard to sea-bottoms, so I am proposing elsewhere (^Report 

 of IrisJt Sea Commiitee) the following amended classification :—(!) Terrigenous 

 ■(Murray), where the deposit is formed chiefly of mineral particles derived from the 

 waste of the land ; (2) Neritic, where the deposit is chiefly of organic origin, and is 

 derived from the shells and other hard parts of the animals and plants living on 

 the bottom; (3) Planktonic (Murray's 'pelagic'), where the greater part of the 

 deposit is formed of the remains of free-swimming animals and plants which lived 

 in the sea over the deposit. 



- Liverpool Marine Biology Committee. 



