president’s address. 
5 
I have selected as the subject of my address — 
THE NATURAL HISTORY OF THE NORTH SEA. 
Although our Society is primarily concerned with the fauna 
and flora of Norfolk, it requires little argument to show that 
the characteristic features presented by a given area cannot 
be adequately estimated until they have been compared with 
those of neighbouring areas. Comparative methods of study 
are particularly necessary in the case of Marine Biology, 
owing to the absence of obvious barriers to the dispersal of 
marine organisms, our relative ignorance of the factors which 
determine distribution, and the difficulties which confront all 
efforts to expose the conditions of existence for species which 
live belowthe tidal zone, beyond the reachof direct observation. 
Assuming that we possess a fairly complete knowledge of 
the coastal fauna of a given area, it is impossible to understand 
the causes of the observed distribution, to know why one 
species is rare and another abundant, or why a given species 
attains a larger size in a neighbouring district than in our 
own, or vice versa, until we know what are the dominant 
influences at work in adjacent waters, and are able to dis- 
tinguish between those which are regular and normal and those 
which are irregular and of less frequent or less powerful 
character. 
The history of Marine Biology may be said to have passed 
through the following stages : firstly, the pioneer investigations 
of individual naturalists, such as Otto Muller and Sir^John 
Dalyell, who laid the foundations of later knowledge by describ- 
ing in comprehensive manner the local fauna of particular 
portions of the coast ; secondly, the period of the monographers 
such as Forbes, Gosse, Alder and Hancock, Allman, Hincks, 
and McIntosh, who took up the study of special groups, gave 
precision to vaguely described or previously unrecognised 
species, and summarised the knowledge of the time concerning 
their distribution and habits of life ; thirdly, the period of 
