4 DE. G. H. FOWLEE— BISCATAN PLANKTON: 



As regards the state of the sea, it raust be remembered that " smooth " in a sailor's 

 mouth often covers enough swell to break Medusae and Siphonophora to hits in the net, 

 and to make it difficult to work deep-water nets. 



The depths marked with a + were the greatest depths to w^hich a net was lowered 

 each day and found no bottom. 



In Table II. are given the more variable data. 



All the hauls were made with open tow-nets, except where only the time of arrival 

 on board is given in the second column, these hauls being taken with the closing Meso- 

 plankton net. 



In the third column, headed ** Net," is given the number of meshes per linear inch : 

 a matter of importance in dealing wdth minute animals. The nets w^ere made of the 

 ordinary Swiss Boulting Silk familiar to marine zoologists (except 65, which was of 

 muslin). 



The fourth column shows the horizon investigated. In the hauls marked 25, 50, 75, &c. 

 to 0, the net was lowered, towed for some time at the lowest level, and pulled straight up 

 to the surface again as rapidly as was safe. As has been pointed out above, these nets 

 may have towed a little above the depth indicated, in some cases where the ship's drift 

 was considerable ; but I do not think that, used as they were on a |" circumference wire 

 rope with a 19-lb. sounding-lead, they are likely to have risen much above the theoretical 

 depth. 



As regards the deeper hauls, there were in the regular series : 



7 hauls from 200 to lOOl 



200 I 



r*100-fathom sections, 

 300 I 



4.OOJ 



500"" 



750 

 1000 , 

 1250 J 

 1500 500-fathom sections ; 



and also as extra hauls round a supposed " critical " depth, there were : 



1 haul from 150 to 50, 

 1 „ „ 150 „ 100, 

 3 hauls „ 250 „ 150. 



The collection may therefore be expected to yield a fair picture of the smaller Meso- 

 plankton. 



The actual bulk of water from which the fauna is strained by these deep-water 

 nets is very small ; and this point must not be forgotten when organisms are only occa- 

 sionally captured, or seem few and far between in the deeper hauls. Thus with the 

 ordinary 20-inch- square Mesoplankton net in the tables just given : 



100-fathom section strains 1650 cubic feet, 



250 „ „ 4125 „ 



500 ,, „ 8250 „ 



of which even the last is less than the cubic contents of a fair-sized drawing-room, 

 2 0' X 30' X 14' high. 



)*250-fatliom sections, 



