28 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
described and demonstrated, both by experiments in the 
Laboratory and observation in the Aquarium tanks.”’ 
It may be useful to place on record also a list of the 
oceanographical nets and instruments and other pieces of 
apparatus that were described and shown in action, either 
in the laboratory or at sea, during the course :— 
Hensen’s closing quantitative tow-net (Petersen’s modification), 
No. 20 silk. 
Nansen’s closing tow-nets (3 sizes, 1 metre, 50 cm., and 35 cm. in 
diameter), various grades of silk. 
Apstein’s smaller tow-net, No. 20 silk. 
Ordinary horizontal tow-nets of various sizes and patterns, and sizes 
of mesh. 
Large Shear-net (for mid-water work). 
Petersen’s Yngel-trawl. 
Apstein’s Plankton-rohre. 
Lucas Sounding machine, with 200 fathoms of pianoforte wire. 
Metre wheel for measuring the length of line run out. 
Ekman’s reversing Water-bottle, with thermometers. 
Richard (Monaco) Water-bottle. 
Pettersson-Nansen Insulated Water-bottle. 
Set of Kiel Areometers. 
Ekman propeller current meter. 
Negretti and Zambra deep-sea reversing thermometer. 
Richter’s reversing thermometer. 
International standard surface thermometers. 
Microscope adapted for counting plankton organisms. 
Kiel Stempel-pipettes ; and other laboratory microscopical accessories. 
Burettes and pipettes for chlorine estimations ; and other accessories 
for chemical work. 
Dredging derrick, leading blocks, steam capstan, hand winding reel, 
with 200 fathoms steel wire rope and brake. 
Beam trawl, otter fish trawl, Agassiz trawl. 
Naturalist’s dredges of various sizes and patterns; rope tangles, etc. 
Sorting sieves, collecting jars and tubes, fish tins, and other accessories 
of collecting expeditions. 
PLANKTON OBSERVATIONS. 
The dredging, tow-netting and other investigations 
at sea, started some years ago with the yacht 
‘‘ Ladybird,”’ have been carried on vigorously during the 
Easter and Summer vacations of 1910. Nearly 650 
samples of plankton have been collected this year, with 
various nets (figs. 5 and 6) in the seas around Port Erin, 
and have been sent to Mr. Andrew Scott for detailed 
