THIRTEENTH ANNUAL MEETING. 165 
production from year to year, resulting from the influence of 
natural conditions beyond his control, still persist. 
Confronted with those adverse influences, all the toil of the 
husbandman, all his stores of experience, all the resources of 
science, are powerless to avert scanty harvests, or absolute fail- 
ure of crops. 
What is true of agriculture is equally true of aquiculture, and 
more particularly of pisciculture in rivers. 
The restoration and maintenance of our river fisheries de- 
pends upon our ability to promote conditions favorable to pro- 
duction, and exclude those which are adverse. 
First—The seed of the future harvest must be sown. Where, 
in consequence of the interference of man by excessive fishing, 
or by the destruction of spawning grounds, natural agencies are 
inadequate to produce the young fish in numbers sufficient to 
repair the inroads made by capture or by natural casualties, we 
must supply the deficiency by artificial propagation. 
But the breeding and planting of shad or herring by the sisi 
lion or tens of millions, in an area like the Potomac or the 
James, or the Susquehannah rivers, cannot carry the annual 
product of the fisheries in these rivers beyond a certain maxi- 
mum limit, which is defined, first by the extent of the breeding 
and feeding area acceptable to the fish, and second by the abund- 
ance of food for the fry which is to be found in this area. 
Second—The extension of the breeding and feeding areas to 
their natural limits, by providing practical passes for our ana- 
dromous fishes over the artificial or natural obstructions which 
have contracted these areas, is a second essential condition to be 
fulfilled, and is one of equal or even greater importance than 
the artificial propagation and planting of the fry, because it is 
possible by this means to secure the permanent restoration of 
our river fisheries under natural conditions. 
A third condition, exercising an important influence upon the 
permanence of our river fisheries, has only recently attracted at- 
tention, and offers an inviting and important field of investiga- 
tion. 
We may plant the young of shad or herring in our rivers in 
countless millions, we may extend the breeding and feeding 
