672 
MR. F. BALFOUR BROWNE ON A 
apparently confined to the Dilham sub-district. I only visited 
this locality during July, but having found the species there 
I searched for it in other localities and without success. 
One other species has apparently a very limited area of distribu- 
tion and that is the handsome Calopteryx splendens. It is fairly 
common on the Bure between Belaugh Broad and Bridge Broad, 
and seems to get scarcer down the river as far as Wroxham Broad, 
below which I never saw it. 
Now in considering all these records of local distribution of the 
Dragon-flies, it must be borne in mind that they are the result of 
only one season’s work, my first season in the district, and one in 
which I was consequently somewhat handicapped by not knowing 
my ground. I do not for that reason lay too much stress upon the 
accuracy of the results, but I do not think that my observations 
can have been so inaccurate as to discover a local distribution 
where there was nothing of the kind. I hope, therefore, that you 
have heard enough to be satisfied that there is a basis for the 
scheme which I have propounded to you, and I also hope that it 
will receive your hearty support. 
I do not expect members of this Society who have other things 
than Biology to attend to, to take up large sections of the w r ork. 
The more assistance I can get the more thorough will the work be ; 
but I shall be glad to receive help with regard to the distribution 
of species of any group of animals or plants, or even with regard to 
the distribution of any one species. In fact, any reliable informa- 
tion upon the question will be welcome, as will also any suggestions 
with regard to the scheme which I have laid down. 
I myself hope, during the coming season, to elucidate the facts 
of distribution of the aquatic and semi-aquatic beetles on which 
I have already done some work and also of the Trichoptra or 
Caddis-flies, of course noting at the same time the Dragon-flies. 
We have, therefore, made a start in what I hope will become 
a valuable piece of work, but it can only become valuable by con- 
tinued observation and massing of facts from season to season, and 
I hope that if we can unite this Society and the Sutton Broad 
Laboratory in the working out of this problem, we may be able to 
obtain results which will not only be a credit to the Society and 
the Station, but will also add sound facts to our knowledge of the 
intricacies of the Struggle for Existence. 
