GRADES AND LEVELS 55 
Or clear and excavate still more and turn 
swamp into pool, with a stock of goldfish or 
commoner kinds as mosquito exterminators. 
In this connection let me say that in order 
to insure against mosquito breeding, evei*y tiny 
little water pocket among the grasses and the 
mud at the margin of such a pool or pond must 
be opened to the fish and kept so ; and all over- 
hanging branches of trees or shrubs must be 
cleared away so there shall be no deep shadows 
which they will avoid and so miss the larvae. 
The presence of mosquitoes around a well 
stocked pool is a sure indication that one or 
both of these requirements have not been met, 
for if the larvae are where the fish can get 
them, they will do so. It is only when they 
are shut off from them by grasses or shadows 
that they fail in the mission assigned them. 
The effect of topography upon garden de- 
sign is of course very great. Yet design, even 
upon irregular ground, is governed in a gen- 
eral sense by the same considerations which 
affect it elsewhere, in spite of the great meas- 
ure of liberty which it must have in order to 
conform to the ground’s undulations. For the 
axes are quite as important whatever the 
contours, and the border, framing and holding 
all together, is just as necessary. A design 
