268 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
Bay and in the strong current near the Calf Island, but 
the use we have made of it as yet can only be regarded 
as for the purpose of practising with the instrument and 
testing the method, and has not led to any results that 
can be recorded. 
HYDROGRAPHIC CONDITIONS. 
In last year’s report we had a section, by Dr. W. J. 
Dakin, dealing with the hydrographic observations he 
had made at Port Erin during 1909 in connection with 
our work, and their bearing on the planktology. No 
further observations on the same lines have been made 
systematically this year, and such as have been taken 
do not affect what was printed in the last report 
(Part III, p. 200). As usual, we have the ordinary 
meteorological records made on each plankton expedi- 
tion, and also the records, in air and sea, taken twice 
daily at the Biological Station. 
We insert here, for reference, the chart (fig. 2) of 
air and sea temperatures for 1910; and, for comparison, 
the similar chart (fig. 3) of the previous year—both 
made from the station records by Mr. H. C. Chadwick. 
It will be noticed that, compared with 1909, the sea 
temperature in 1910 was rather higher throughout the 
spring (e.g., in March), the lowest point (41° F.) being 
at the end of January, while in 1909 the temperature 
was at its lowest (40°5° F.) in the middle of March, six 
weeks later. 
In 1910, the air temperature did not rise above that 
of the sea until the second week in May, and then 
remained above until the last week of August; and the 
sea temperature at the end of the year (47° F.) was 
higher than usual; but on the whole the sea-temperatures 
