PELAGIC FAUNA. oO 



show the same liking for the coelenterate group, by browsing 

 on the zoophytes (Obelia geniculata) which cover the stones 

 and rocks with feathery tufts, yet the zoophytes are not much 

 the worse for this treatment, for they by-and-by shoot afresh, 

 and clothe the area once more with a minute forest. The 

 rapidity with which such zoophytes grow is remarkable, though 

 we must remember that in some cases, as in those (Gonothyrcea) 

 clothing the mussels in the Eden, the old stock naturally dies 

 off after having produced swarms of pelagic young. 



General Remarks on Pelagic Life. In the year 1888 one of 

 us prepared a special report 1 on the pelagic animals of the Bay 

 of St Andrews, a region which may be taken as more or less 

 typical for the east coast of Scotland if not for a wider area. 

 The investigations were carried out for a year and summarised 

 for each month. From the results of previous observations 

 made during the trawling expeditions, the pelagic forms may 

 be classified into two great divisions, viz. the Temporarily 

 Pelagic and the Permanently Pelagic. 



In making these observations a different method from that 

 of the Germans, especially Dr Hensen, was adopted. Prof. 

 Hensen sank nets of a special construction, and calculated the 

 amount of water passing through them in a given time, then 

 having counted the various eggs and animals he apportioned 

 them to the cubic foot of water. The method followed at 

 St Andrews consisted of the use of tow-nets at the surface and 

 the bottom, as well as in mid- water, the latter being a large 

 ne t 24 feet in length attached to a triangle of wood or 

 bamboo 10 feet each way and hinged at two of the angles, the 

 third being secured with spun yarn. The mid-water net has 

 been of great service in regard to the post-larval and young 

 fishes, indeed no other known form of net has been so successful 

 in capturing these active forms 2 . If worked from a large 

 steam-vessel this net, which is steadied at the required depth 

 by a heavy bar of lead and floated by a galvanised iron rloat, 

 requires much care in manipulation. 



1 Seventh Ann. Rept. Fishery Board, 1889. 



- Dr Nansen amongst others carried one of these St Andrews nets with him 

 in his expedition to the North Polar regions. 



