136 A NEW ZEALAND NATURALIST'S CALENDAR. 



which do not require the shelter of the plants or stones of 

 the beach. 



To collect them we must employ some kind of fine net 

 and tow it after a boat, and this process is not as easy 

 in execution as in design. Steamers and most sailing 

 boats usually go too fast, and as the stuff of which the 

 tow-net is made must be of very fine mesh, such as muslin, 

 too high a rate of speed simply tears the fabric to pieces. 

 Besides, the opportunities of going out into the open sea in 

 sailing boats are neither numerous nor altogether welcome 

 to the average landsman, so that without special arrange- 

 ents it seems at first sight difficult to secure opportunities 

 of collecting such materials. One method which was 

 suggested and carried into practice by Professor Herdman 

 of Liverpool is both ingenious and successful. A continual 

 supply of sea water is available on board steamers for 

 washing decks and other purposes, and by simply placing a 

 muslin filter under the hose pipe when it was not in 

 regular use he procured a great supply of pelagic material. 

 Indeed on some trips of the Atlantic liners the supply 

 of minute Crustacea was so great that they were cooked 

 and served at table as a special luxury under the name 

 of "shrimp paste" on toast. 



In Otago Harbour I have utilised the tidal current in 

 much the same manner and found the plan fairly suc- 

 cessful. For twenty hours out of the twenty-four the 

 lightship, which was formerly moored in the lower harbour 

 to mark the channel, was in a strong current due to the 

 great ebb and flow of the tide, and on various occasions 

 in past years I have spent the night on board the little 

 craft (in the days when the well-known Griff Jones was 

 lightkeeper), and have kept the tow-net over the side 

 for hours, filling in all spare time in examining and 

 preserving the material collected by it. Such work is 

 always most successful when the air, and consequently the 

 water, are perfectly still, as under such circumstances 

 the small organisms swim right up to the surface. If 

 there is any break on the water they tend to sink to a 

 depth of several feet. Hence I have always got the best 



