964 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
Tore MATERIAL AVAILABLE. 
We have fortunately again been able to make large 
collections, as we consider that in work of this kind it 
is only possible to arrive at sound and reliable con- 
clusions when the data are derived from large series of 
samples. When the present collections are added to 
those of former years, we have now, as the total number 
of plankton-gatherings from a small area of the Irish 
Sea, over 2,500 samples, made up as follows :— 








At sea, from yacht. In Bay 
Year. throughout Totals. 
Spring. Autumn. year. 
1907 218 279 138 635 
1908 156 242 157 555 
1909 329 147 2314 49 756 
1910 107 249 296 652 
_ Totals ...| 810 917 871 2,598 

These are very substantial numbers, and they ought 
to yield reliable conclusions as to the seasonal variations 
in the plankton throughout the year, and as to the 
characters of individual years. It is unnecessary to 
repeat what we said last year (Part III, p. 195), as to 
the values to be attached to our different nets, and as to 
the comparability of our hauls one with another. 
OUTLINE OF THE YEAR’S WorK. 
Throughout the year 1910, from January 3rd to 
December 30th inclusive, “ official’? gatherings were 
taken across Port Erin Bay, by the staff of the 
Biological Station, generally twice a week, and some- 
times more frequently. On each such occasion two 
surface hauls were made, one with a coarse and the 
other with a fine net, and after January a third 
