BIONOMICAL INVESTIGATION OF TTIE NORFOLK BROADS. 665 
In other words, we shall find numbers of species of the various 
groups cosmopolitan in the district, but it is not these species 
which will directly concern us. It is safe to say that some species 
will be present in one part of the district and absent from another, 
and I think it highly probable that the distribution of a species 
will vary from season to season. The variation in the distribution 
of one species will probably involve a rearrangement of other 
species, and thus I hope that from year to year we shall find 
interesting changes going on in the fauna and flora, and that 
such observations will indicate to us definite problems of inter- 
relationship to be solved. 
I conceive that most of the bionomical work which has been 
done up to the present time has been carried out “ piece-meal.” 
Small problems, chosen without any reference to their connection 
with the problem of the general struggle for existence, have been 
investigated, and have failed to give us results of intrinsic value. 
By first surveying the whole struggle as carried on within a limited 
district, it seems to me that we can select the problems worthy of 
inquiry and that the investigation of such problems will have 
a definite value in relation to the whole question of bionomics. It 
is the inter-relationship of a species with all those with which it 
comes in touch that is the ultimate problem, not merely its 
relationship with its food or with those species which prey upon it, 
and the question ich y a species has a localised distribution is only 
to be answered by discovering the part it takes in the great struggle 
for life. This, I submit, may be done by tracing its distribution 
over a small area in conjunction with that of all other species 
which live with it side by side, and which may or may not affect 
its existence. 
For such a scheme of work as that which I hlfve laid before you 
the District of the Norfolk Broads is eminently suitable. We 
have a series of Broads all connected more or less intimately into 
one system by waterways in which the water flows scarcely quicker 
than in the Broads. Round many of these Broads and along most 
parts of the rivers and dykes connecting them are extensive 
marshes, and in these marshes and their environs are numerous 
small waterways draining the land. 
The District of the Norfolk Broads was defined by Lubbock 
(‘Observations on the Fauna of Norfolk, 1879,’ pp. 78 and 79), as 
x x 
VOL. VII. 
