MARINE BIOLOGICAL STATION AT PORT ERIN. 59 



which the area was then divided may prove useful to 

 observers in fixing localities. The exact distribution of 

 even the commonest species, the relative abundance in 

 different habitats, and at the same place in different 

 years, the presence of varieties in some localities and 

 not in others, and the comparison of large numbers of 

 individuals from exposed and from sheltered, from 

 shallow and from deep, from clear and from turbid 

 waters, are amongst the problems or lines of work 

 included in the intensive study of a small area. 



The next two sections of this report, on the Plankton 

 Investigations and on the Comparison of three Fishing 

 Banks off the Isle of Man, are both of them further 

 examples of intensive study of small areas which have 

 been carried on during the last year, and will be continued. 

 But in addition to these, which can only be conducted at 

 sea, from a steamer, I desire especially to direct renewed 

 attention of all workers at Port Erin to the necessity of 

 taking up again with energy, and in co-operation, that 

 systematic survey of the bay which we started in 1900. 



Plankton Investigations at Port Erin. 



It will be remembered that in last year's Report I 

 published the results of observations made the previous 

 summer off Port Erin, which tended to confirm the belief 

 that the plankton (minute suspended organisms in the 

 sea) has no such regularity and uniformity in distribu- 

 tion as is sometimes supposed. The importance of the 

 matter lies in this — that if there is not this perfect 

 uniformity over wide areas we must not attempt to draw 

 general conclusions from comparatively few and distant 

 observations. We must learn the meaning and relative 

 values of our samples by the intensive study of small 



