P' May 9. 1889] 



NATURE 



47 



THE LIVERPOOL MARINE BIOLOGY 

 COMMITTEE'S EASTER DREDGING CRUISE. 



'T'HE Liverpool Salvage Association's s.s. Hynsna left the 

 ^ Mersey on Thursday, April 18, on her fifth scientific 

 cruise under the direction of the Liverpool Marine Biology 

 Committee. The old gunboat had been generously placed 

 at the disposal of the l^.M.B.C. for five days, and the pro- 

 posed course was to cross to Port Erin, at the south end 

 of the Isle of Man, and then dredge southwards to Holyhead 

 through the deepest water to be found in this district ; then 

 to work along the coast of Anglesey to Puffin Island, and 

 from that back to Liverpool. Besides the ordinary dredging and 

 tow- netting operations, it was hoped that two interesting new 

 methods of collecting would be tried on this cruise : (i) the sub- 

 marine electric light, which gave such good results in the Hyana 

 expedition of last summer, was to be used as an attraction in the 

 nets let down to the bottom at considerably greater depths than 

 was the case in last year's experiments at Ramsey and Port Erin ; 

 (2) Mr. W. E. Hoyle's new tow-net (recently described in the Proc. 

 Biol. Soc. Liverpool, vol. iii.), which can be opened and closed 

 at any required depth, so as to insure that the contents were 

 captured in a particular stratum of water, was to be taken with 

 the view of trying how it worked. 



After the first day, however, the weather although fine on land 

 became very unfavourable for marine work, and the programme 

 had to be considerably altered. Thursday was spent in crossing 

 to Port Erin. On Friday morning we steamed south-west 

 towards the deep water, but a strong wind was blowing, and 

 after a haul of the dredge in 27 fathoms, about five miles out, 

 some bottom and surface tow-netting, a sounding in 50 fathoms, 

 and a further run to about nine miles from land, it was found 

 that the heavy rolling of the vessel rendered dredging operations 

 impossible out in the open sea ; so the Hyana was put about and 

 returned to Port Erin, where tow-netting and other work was 

 carried on in the bay. The following day the wind was still 

 stronger, so it was decided to give up the Anglesey part of the 

 cruise and devote the remaining days to shore and shallow-water 

 work round the south end of the Isle of Man. Accordingly the 

 rocks at Port Erin, Port St. Mary, Poyllvaaish Bay, and 

 Fleshwick Bay were explored on the third day, while on the 

 fourth most of the day was spent on board the Hyana, at anchor 

 in Port Erin Bay. Tow-nets were let down, both on the surface 

 and weighted so as to reach the bottom, and a small dredge with 

 a long canvas net was taken out in a boat and used for obtaining 

 samples of mud and sand to examine for small animals, such as 

 Foraminifera, Copepoda, and Ostracoda. The strong wind 

 blowing was utilized by Captain Young, who suggested floating 

 tow-nets across the bay with life-buoys, and devised a sailing 

 apparatus, consisting of an old life-buoy rigged up with a mast 

 and sail, and having a tow- net suspended from it, which was let 

 out carrying a long line to leeward and was then hauled in, the 

 net keeping distended and working well during both the outward 

 and the return journeys. Another surface-net was even rigged 

 up attached to a large kite, but this did not work satisfactorily. 



In the afternoon the Hy(cna made two runs from Port Erin 

 southwards to the Calf, dredging homewards with the wind, and 

 got two excellent hauls, which contained amongst other things : 

 Sarcodictyon catenata, Stichaster roseus, Palmipcs tnembranaceus, 

 Porania pulvilhis, Adamsia palliati, and Fagurus pridcauxii, 

 Ehalia sp., Lyonsia norvegica, Pectunculus glycimeris, and 

 Ascidia venosa. 



After dark on two consecutive nights the electric light was 

 used for a couple of hours in collecting bottom and surface free- 

 swimming animals round the ship, in much the same way as 

 during last summer's cruise. A pair of large arc lamps of 20CX) 

 candle-power each were hoisted up in such a position as to 

 illuminate the deck and cast a bright light on the water for some 

 distance on each side of the ship. Three submarine incandescent 

 lamps of ;o candle-power each were then fitted in the mouths of 

 tow-nets and were let down, two of them to the bottom at a 

 depth of 5 fathoms, and the third to a foot or so below the 

 surface of the sea. Each of these nets was put out twice, so that 

 we got four bottofn hauls and two surface hauls with the electric 

 light tow-nets. Another tow-net, without any lamp, was let over 

 the side of the Hyana, and lay in the brightly illuminated 

 surface water. All these nets were stationary, but were kept 

 fairly distended by the tide. At the same time Mr. I. C. 

 Thompson was rowed round and round the ship dragging an 

 ordinary tow-net in the bright area. Consequently all the nets 

 were, on this occasion, used in water lighted up, the surface n°ts 



being in the glare of the 4000 candle-power lamps, while the 

 bottom nets were further from this bright light, but had each 

 their own smaller lamps. All gave, so far as we yet know, from 

 a cursory examination, practically similar results which are 

 markedly different from both the bottom and surface gatherings 

 taken at the same place during the previous day, T he electric 

 light gatherings contain chiefly Schizopoda, Cumacea, Amphi- 

 poda, and a few Copepoda. The Cumacea are the most marked 

 feature, they are veiy abundant, and form a conspicuous charac- 

 teristic in t'le gathering whenever it is transferred from the net 

 into a glass jar. In none of the daylight tow-nettings, either 

 bottom or surface during the cruise, was a single Cumacean^ 

 obtained, while every gathering on the two nights when we had' 

 the electric light going contained Cumacea in abundance. I 

 think there can be little doubt that those captured in the 

 surface-nets had been attracted from the bottom by our brilliant 

 deck-lights, which had been shining for fully half an hour before 

 the nets were put over. 



On the fifth day the Hyana started in the morning from Port 

 Erin and arrived at Liverpool at midnight. A little dredging 

 and tow-netting was done on the way. A good haul was 

 obtained from a stony and shelly bottom, at about 15 miles 

 south-east of the Chicken Rock, depth 30 fathoms, which yielded 

 large numbers of Polyzoa, chiefly incrusting forms. At this 

 spot also, it being the deepest water on our track from Port Erin 

 to Liverpool, we let the electric lamp down to the bottom in a 

 tow-net twice, and got gatherings consisting mainly of Copepoda, 

 Sagitla, Amphipoda, Zotias, and other larval forms. 



That free-swimming Crustaceans are attracted to a stationary 

 net by the electric light may now be considered established beyond 

 doubt ; and that the illuminated tow-net can be used in, at 

 least, such moderately deep water as is commonly met with in^ 

 dredging round our coasts was evident to all who saw the success 

 with which the net was worked on board the Hyana in 30 

 fathoms. 



The various tow-net gatherings and dredged collections were 

 as usual preserved and brought home, and are now in the hands 

 of the specialists who are working at the different groups of 

 animals for the Liverpool Bay "Fauna." 



W. A. Herdman. 



SOCIETIES AND ACADEMIES. 



London. 



Linnean Society, May 2. — Mr. C. B. Clarke, F.R. S., m 

 the chair. — With reference to a recent exhibition, by Mr. D. 

 Morris, of leaves of different species, or varieties, of plants in- 

 cluded under ErytJiroxylon Coca, Lamarck, Mr. Thomas Christy 

 made some remarks on the leaves of a variety from Japan. 

 These he described as brittle and thin, with hardly any trace of 

 cocaine, though yielding 8 per cent, of crystallizable substance. 

 The thicker leaves of the Peruvian plant yielded more cocaine, 

 though at first rejected on account of their more glutinous- 

 nature. — Mr. John Carruthers read a short paper on the 

 Cystocarps, hitherto undescribed, of a well-known seaweed, 

 Rliodymenia palmata, upon which remarks were made by Mr. 

 G. Murray and Mr. A. W. Bennett. —The second part of a 

 monograph of the Thelephorea was communicated by Mr. G. 

 Massee. — Mr. Mitten contributed a paper on all the known 

 species of Musci and Htpatica recorded from Janan. An in- 

 teresting discussion followed on the character of the lapanese 

 flora, in which Mr. J. G. Baker, Dr. Braithwaite, and Mr. G. 

 Murray took part. 



Geological Society, April 17.— W. T. Blanford, F.R.S.,- 

 President, in the chair. — The following communications were 

 read : — On the production of secondary minerals at shear-zones 

 in the crystalline rocks of the Malvern Hills, by Charles Calla- 

 way. In a previous communication the author had contended 

 that many of the schists of the Malvern Hills were of igneous- 

 origin. Thus, mica-gneiss had been formed from granite, horn- 

 blende-gneiss from diorite, mica-schist from felsite, and in- 

 jection-schists from veined complexes which had been subjected 

 to compression. As a further instalment towards the elucida- 

 tion of the genesis of the Malvern schists, he discussed the 

 changes which the respective minerals of the massive rocks had 

 undergone in the process of schist- making. — The northern slopes 

 of Cader Idris, by Grenville A. J. Cole and A. V. Jennings. 

 From the publication of Mr. Aikin's paper in the Transactions 

 of the Geological Society in 1829 lo the second edition of the- 



